1 week pregnant
First trimester less than a month
At 1 week pregnant, conception hasn't happened yet — pregnancy is dated from the first day of your last period.
Baby this week
By clinical dating, pregnancy is counted from the first day of your last menstrual period — but conception hasn't happened yet. This week your body is menstruating and preparing for ovulation, which typically occurs around day 14. There is no embryo this week.
Did you know? Pregnancy is dated from the first day of your last period — not from conception. This means you're counted as 'pregnant' during weeks 1 and 2 before an egg has even been fertilized.
What she may be feeling
- Menstrual bleeding (this is your period)
- Period cramping
- No pregnancy symptoms — conception hasn't occurred
- Body is preparing for ovulation
Tips for her this week
- Start prenatal vitamins with 400–800mcg folic acid immediately if you haven't — ideally before conception.
- Avoid alcohol, raw fish, deli meats, and high-mercury fish.
- Schedule your first OB appointment — ideally for around week 8–10.
- Begin noting any symptoms, even subtle ones, to share with your doctor.
For partners
- Pregnancy is just beginning — now is the time to start thinking about lifestyle changes like reducing alcohol and improving sleep.
- Support her in starting prenatal vitamins with folic acid if she hasn't already.
- Begin researching what the first trimester involves so you're not caught off guard.
- This is a private, tender moment — protect it and enjoy it just between the two of you.
Partner to-do list
- Start reducing alcohol intake
- Research first trimester basics
- Have a conversation about who you'll tell and when
- Support her in starting prenatal vitamins
This week together
- Begin prenatal vitamin routine
- Discuss timeline for sharing the news
- Review health insurance for prenatal coverage
When to call your doctor or midwife
Contact your care provider right away, or call emergency services, if she has:
- Heavy bleeding
- Severe abdominal pain
- Fever over 38°C
Trusted guidance: NHS: Pregnancy · NHS: Pregnancy complications · ACOG: Pregnancy · Pregnancy Info: Your pregnancy
Common questions
How big is the baby at 1 week?
At 1 week pregnant, conception hasn't happened yet — pregnancy is dated from the first day of your last period. There's no measurable baby size yet.
How many months is 1 week pregnant?
1 week pregnant is less than a month, in the first trimester.
What can partners do at 1 week?
Pregnancy is just beginning — now is the time to start thinking about lifestyle changes like reducing alcohol and improving sleep. Support her in starting prenatal vitamins with folic acid if she hasn't already.