Am I pregnant?

So I'm 16 and my boyfriend and I have sex quite often. We always wear condoms, but he doesn't pull out when he has finished. We had sex a few days ago and I've been getting odd cramp type things kind of near my ovaries. I just had my period, but <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> said i wasn't fertile when I had sex. So is this something that happens if you're pregnant or does this happen to some people after their period as well? My period cramps are horrible. Enough to make me cry, but what I have been experiencing the past few days is just kind of a dull pressure. I'm just kind of freaking out and would like some answers. So if anyone could help that would be much appreciated