My last menstrual period was on the 7th Jan 2012 and my cycle is 33 days long how many weeks pregnant am I?

About 5 weeks and 1 day. Dr. M

Predicting conception dates is an inexact science. Any guess is just that a guess.

An ultrasound will give give you a better idea, but that won't happen for some time.

Why are you concerned? Is there a question of parentage? If that's the case then knowing how far along you are really won't help. Only a DNA test can determine parentage.

Good luck.

Actually, if your LMP was 1/7/12, and since this is 2/18/12, you are exactly 6 weeks along as calculated by the conception calendar the OB's use.