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!
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.
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.