How many days after your period do you ovulate?

Question

Just wondering as I'm trying to figure out when I actually got pregnant as my doctor told me two different due dates. So when do you normally ovulate and how long is you whole cycle? I usually get my period between every 35 to 40 days apart so I figured I ovulate later cuz as I have read that if you have a smaller cycle like 28 days you can ovulate as early as the day after your period. So I'm trying to see different peoples schedules on period an when they normally ovulate. Or if you think you can fig out when I got pregnant I had my LMP Feb 24 to march 2 had sez the 3rd and then the 6th an a couple times between the 10th and 16th and she said my first due date is Dec 1st as of the period and then said Dec 7th as of the first ultrasound but didn't change my due date kept it the first since its so close. Just trying to know since it took me 7 years of off an on trying an never did ovulation testing an wanna kinda know around when so we can try again after she is born. Thank you!

Answer

To add: I think you got pregnant between the 10th and 16th. 
That dates fell in your possible calculated fertile window..

Answer

You do not ovulate a certain amount of days after menstruation, but rather a certain amount of days before your next period. Thats because your Luteal phase is normally always the same, where as your follicular phase can change every month. On a 35-40 day cycle, you could have ovulated on cd 21-26, give or take a day or two.
You're fertile window would then be from 5 days before to a possible 2 days after your Ovulation date.
Having said that, nothing is set in stone, every woman and cycle is unique, some woman's phases and change for different reasons.
The best way for you to know on your cycle, will be OPK's. 
Your date of expected delivery will be from your first day of your last menstruation though.
Hope this helps with your next baby😀👍