A dumb question: I know I conceived on January 22, so how many weeks pregnant does that make me?

The due date calculators all give you a pregnancy week based on LMP. Well, my cycles are 31 days long, and again, I know that I conceived on day 18 of my cycle.

So am I 3 weeks? When do I turn 4 weeks?

(I am clearly math challenged!)

To my knowledge most all doctors use the first day of your LMP and assume that you have a 28day cycle (whether you do or not) So Based off of that you would be due October 11th and be 4w1d. Assuming that your LMP was on Jan 4th. Make sense? I think you would be 3w4d if you were calculating based of conception.
Of course I could be wrong lol

Gestational Age : You will be 4 weeks on the 5th.
Developmental Age : You would be 2 weeks on the 5th.
Someone chime in here and tell me I got that right!
Pretty much all the pregnancy calendars, etc. use gestational age.

http://www.tryingtoconceive.com/eddc.htm

That site will calculate EDD from ovulation date. Based on 1/22 as ovulation date, the EDD is 10/15. If you put that in to all the pregnancy calendars and stuff it will tell you weeks. I think you'd be at... 3w4d, so what sh118 said :)

I lurk here. :lol

I like this calculator (http://healthlink.mcw.edu/article/923526833.html)...granted it's based off a 28 day cycle but you canfiddle around until you get the right dates where you need them. If you conceived on the 22nd your LMP would be Jan. 8 and you are 3 weeks and 5 days pregnant today.

Using a calculator that allows you to change your cycle length your LMP is Jan. 5. I used this one (http://www.citranatal.com/Fun_Stuff/Due-Date-Calculator.aspx) for that. You're still 3 weeks 5 days. Just a matter of changing your LMP date. :)