1 year ttc with no luck.

Ok so I’ve been ttc since November 2019. I got pregnant with my first accidentally within a couple months of losing my virginity so I never used ovulation tests. Since I’ve been ttc with no luck for over a year now I decided to try the ovulation tests to see if I’m actually ovulating since I wasn’t getting pregnant. I got my peak the second day of using the ovulation test so Ik for sure I’ve been ovulating ! So I was wondering , have any of you ladies ovulate regularly and still not be able to get pregnant or do y’all think I might not be the problem ? I have a regular 28 day cycle every month I got my peak on CD 15 of this month. Me and my fiance are both 19 so I thought it wouldn’t be a problem getting pregnant.... I set an appointment to see a doctor on Monday to test both of us but I was just wondering if anyone else had this problem. I thought I should also add that my fiancé is not my son’s biological dad so he doesn’t have any kids of his own. We also have plenty of sex most of the time more than once a day. So I couldn’t have missed my ovulation in the past.