Do I need a period to ovulate? Really confused.

I'm 17 and I've never had a period naturally before because my brain (according to my doctors) doesn't release hormones in sync with my body clock, it's really confusing. Anyway I just wanted to know if I need to have a period to ovulate or if I can work it out normally. I don't bleed but each month I get all the typical symptoms of PMDD which my doctor suggested I have because of the severity of my symptoms like sadness and pain etc. please help I've never really had anything explained to me in detail and it feels pathetic that I don't know about this stuff.

U aren't pathetic. I didnt know about it until just a little while ago. Women ovulate about two days after their period starts. Don't feel dumb.