Getting Pregnant

So my fiancé and I have decided to start trying to get pregnant. We have realized an issue.. My period is so irregular I'm never really sure when exactly I'm ovulating because it's like a surprise to even get my period... We were intimate like a week and a half ago and that was the first time he "came inside me" like 3 days in a row and then the app said I was supposed to be on my period (sometimes It notices how irregular I am and adjusts itself to my actual schedule. Weird right?!?) but sometimes it's wrong too.. But during the time it said I was supposed to be on my period I actually just started spotting.. And it's weird because I've never spotted before.. But I can't help but to get my hopes up and think that everything I'm feeing is a symptom of pregnancy.. I've taken a test even though it's only been a week and a half (I know it can be inaccurate) and it's just really getting me down because I really do feel like things are different but I just need someone to tell me what I should do about not knowing when I ovulate.. Thanks girls!