It goes by the first day of your last menstrual cycle. So if your last menstrual cycle was Nov 22nd, that would make you 5 weeks pregnant with a due date of Aug 29th.
It's confusing the first time but the lady above is right, if you have periods spaced 4 weeks apart your due Aug 29th.
Your dr will confirm st your at usually with an internal ultrasound what weeks you are.
Congrats on the baby!
Guess what guys u was right I did another test the clear blue with the weeks and it says 5 weeks!!! Thanks so much!!