My boyfriend and I have been having sex for a little over a month now, and we haven't been using any source of protection. We use withdrawal and that's it. We keep on bugging each other to be condoms. But meh. We haven't had sex anywhere near my ovulating date though. When I started onus app, I don't think I had my period exactly right on the dates.. But.. It says I'm one date late for my period. Should I be concerned? I'm 17. So my periods are very consistent yet.