How do i calculate when I ovulate? Or if i do ovulate?

I'm 19 and have been on different contraceptive pills for roughly 5-6 years. I also tried the contraceptive injection in 2013 but only for one period of three months. I stopped taking any contraception at the beginning of January 2015 and have had two periods quite regular. Me and my partner have had unprotected sex when I was off contraception for 5 months and I didn't fall pregnant. It's Made me a little concerned that I might not ovulate. I've tried using ovulation tests and none come back positive. I'm late for my period but I took a test couple of week ago but it was negative. What can I do? How do i find out if I ovulate and when?

If you have a period, then you are ovulating. Have you and your partner both been checked to see if there are other issues, low sperm count, etc?

Ovulation takes place approximately 14 days before the "expexted" date of your period [which of course makes it a bit difficult to calculate unless you are ususally "regular as clockwork"].  Simply having unprotected sex about the date that you calculate you should ovulate does increase your chance of getting pregnant but even having intercourse at the "right time" does not guarantee a pregnancy [thank goodness ...]

You only stopped taking contraception within the last two months and your body may take a while to settle down

Your period is late; you "may" be pregnant!   Let us know perhaps...

​=12.0ptIt is just that your body is getting adjusted to contraception–free state. Give it some time. However, if hpts are coming negative and still no period, you should visit a gynaecologist and order a blood test to confirm the result. Negative opks tests, doesn’t necessarily means you’re not ovulating, you might be missing surge. To understand timing of ovulation, keep watch on other physical signs. Start taking basal body temperature every morning, preferable at the same time of the day and keep charting. Make sure that day one on the chart is the first day of menstruation. Just after ovulation, there should be a rise of approximately 0.4-0.6 degrees Fahrenheit (about 0.2 degrees Celsius). On the day of ovulation there will be a slight rise and it will continue to climb progressively higher for next two days. After months of practice, you will get fair idea about your cycle. Also keep looking for egg white resembling cervical mucus. This period indicates high chance of pregnancy.