I would just go with what your OB says because different websites say different things. At least until your first ultrasound if you haven't had one already.
But I would say 3 months going into your 4th month.
You have completed three months making you 3 months pregnant. You are now currently in your fourth month, at 16 weeks your will have completed your fourth month and will be a full 4 months pregnant, you are in your second trimester.
As of right now, you have completed 3 months and you are working on month 4. If you want to be specific, you are 3 months and one week pregnant and in your second trimester
Every 3 months there is an extra week, otherwise there would be 48 weeks in a year instead of 52. So 13 weeks is the end of the 3rd month and 14 weeks is the beginning of the 4th month.
Comments
But I would say 3 months going into your 4th month.
So:
1wk-4wks --1 month
5wks-8wks --2months
9wks-12wks --3months
13wks-16wks --4months
17wks- 20wks --5months
21wks- 24wks --6months
25wks- 28wks --7months
29wks- 32wks --8months
33wks- 36wks --9months
37wks- 40wks --10months
As of right now, you have completed 3 months and you are working on month 4. If you want to be specific, you are 3 months and one week pregnant and in your second trimester