Dog Pregnancy Calculator — Due Date & Stages

How to use this dog pregnancy calculator

Pick the date your dog was bred from the date picker. The calculator returns the expected whelping (birth) date, the current week of pregnancy, and which developmental stage your dog is in today. It also shows the normal variance — puppies can arrive 5 days early or 5 days late from the average 63-day mark.

For multiple breedings across several days, use the last breeding date as your calculator input. Fertilization usually occurs 2–3 days after mating, so this gives the most accurate due date.

Canine gestation overview

Dog pregnancy lasts an average of 63 days from breeding, but the normal range is 58–68 days. Most dogs whelp between days 60 and 65. Going past day 68 without labor warrants an urgent vet call — possible complications include uterine inertia or stress requiring intervention.

Note: the 63-day average is from ovulation, not mating. Sperm can survive 2–7 days in the reproductive tract, so actual conception date varies. This is why pregnancy can appear to range from 56–72 days counted from mating date.

Stages of dog pregnancy week by week

Weeks 1–3 (Days 1–21): Embryo development

• Fertilized eggs travel to uterine horns
• Embryos implant around day 17–21
• No visible signs yet; behavior may be slightly calmer
• Avoid any live vaccines, high-stress situations
• Maintain normal nutrition and exercise

Weeks 4–6 (Days 22–42): Fetal growth

• By day 28, a vet can confirm pregnancy with ultrasound
• Nipples begin enlarging and darkening around day 30
• Appetite often increases around day 35
• Visible belly swelling starts around day 40 in some dogs
• Morning sickness may occur briefly (mild, self-resolving)
• Start introducing puppy food if not already on high-calorie diet

Weeks 7–8 (Days 43–58): Final development

• Puppies are now fully formed, mostly gaining size and fat
• Ultrasound can reliably count puppies (X-ray around day 55 is more accurate)
• Mom's appetite peaks; feed 2–3 smaller meals per day
• Exercise: reduce intensity, maintain short daily walks
• Start preparing the whelping area

Week 9+ (Days 58–68): Whelping window

• Rectal temperature drops 1–2°F in the 24 hours before labor (normal is ~101.5°F)
• Nesting behavior, restlessness, loss of appetite
• Stage 1 labor: 6–12 hours of contractions, dog appears uncomfortable
• Stage 2 labor: active pushing, puppy delivery every 30–60 minutes
• Stage 3 labor: placenta delivery after each puppy

After day 68:

• Contact your veterinarian
• Persistent overdue pregnancy may require medical intervention
• Temperature, contraction patterns, and puppy viability should be checked

What to monitor through pregnancy

Weight: expect 20–50% gain by whelping. Small breeds less (20–30%), giants more (30–50%). Sudden major gains warrant a vet check.

Appetite: increased by week 4–5, may decrease in final week before whelping.

Nipple and mammary development: enlarging, darkening, some milk production in final week.

Discharge: slight clear discharge is normal in late pregnancy. Green, brown, or bloody discharge before labor = emergency vet call.

Behavior changes: becoming more affectionate or more reclusive are both normal.

Preparing the whelping area

Start setting up around day 50 to let mom get comfortable with the space:

• Whelping box: larger than her usual bed, with sides high enough to keep puppies contained but low enough for her to enter easily (8–12 inches)
• Line with layers: towels or pee pads over newspaper. Lots of layers — they'll need changing frequently
• Location: quiet, dim, warm, accessible. Avoid high-traffic areas
• Temperature: 85–90°F for the first 5 days of puppies' lives, then can reduce
• Heat source: heat lamp OR heating pad at one end of the box (never both)
• Supplies within reach: clean towels, hemostats, dental floss, iodine, thermometer, scale, puppy milk replacer (emergency backup)

When to call the vet

Normal pregnancy doesn't need constant monitoring, but these situations warrant an urgent call:

• Before day 58: any bleeding, green discharge, or active pushing without delivery (premature labor risk)
• Days 58–68: temperature below 99°F for more than 24 hours without whelping starting (possible uterine inertia)
• Active labor: pushing for more than 60 minutes without a puppy, more than 2 hours between puppies, or mother becomes exhausted
• After whelping: retained placenta (count placentas = count puppies), fever, lethargy, excessive bleeding, refusal to care for puppies
• Any time: your instincts saying something is wrong. Vets far prefer a false alarm to a delayed emergency