still unsure

i dont relly know why im bothered but im really confused about my dates, my periods were never that regular but im pretty sure my last 1 was the last week in april so at the latest the 29th but the ultra sound scan dates me as being 13 weeks and 1 day today, if my dates are correct then i should be further on than this?! they say that from the scan my last period was may 6th but i know it was in april at some time otherwise i wouldnt have thought i was pregnant? i read on google that most women ovulate round 2 weeks after the first day of there last period so when does that mean i actually fell, do u count the weeks from the first day of the last period or the 2 weeks after when you are likely to ovulate? its well confusing can any1 work out from my dates when i actually fell pregnant, and how accurate are these ultra sound scan dates?

[KM604]

Ok, well yes it is true women usually ovulate 2 weeks after the first day of their period - that is for a women on a normal 28 day cycle.  Actually, you ovulate around 2 weeks BEFORE your next period.  So if you aren't normal (your period that is), it is hard to determine when you ovulate.  You may have ovulated later (because your cycles aren't regular), which would cause your last period date to be later.  It's really confusing but ovulation is determined by when your next period is, not on your most recent period.  For me, I know when I ovulate based on cervical mucus.  Everytime I get cervical mucus, no matter when my last period was (because trust me I was very irregular), I would get my period exactly 14 days after the cervical mucus.  My period and ovulation was all normal the month I conceived, and I was still 3 days behind what I thought based on my last period.  So even if you do think everything was normal, if is possible for your dates to not be so accurate.  It is possible for u/s scans to be off, but not by too much.  I wouldn't worry - talk to your doctor though if you are.

[leighanne143]

since your periods are not regular, that is a sign that you might not ovulate right 2 weeks later.  so it seems like you ovulated later than your period says, which happens to many women,

as long as you had a good ultrsound and theres a healthy heartbeat, try not to stress.

[Atlantisea]

Your ovulation was likely to have been delayed and/or effected by your choice of lifestyle... Cocaine mucks womens menstral cycles around a bit.

Don't worry, when you ovulated won't have any effect on your baby's health.

Everything should be fine!