you probably ovulated late in your cycle.
according to my lmp, i am 5 weeks along but i know that can't be the case. because 2 weeks ago, on day 22 of my cycle, we started unprotected sex. i have no idea if i ovulated on day 21, 22, 23, or 24...no idea. but i got my BFP over the weekend. i think i am 4 weeks a long, not 5 weeks.