Intense pain when peeing

So just last Friday I had sex for the first time. And then again on Saturday. It hurt a little but not as bad as I thought it would. On Sunday night I had cramp like pain and now today (Monday) I've been going pee a lot, but not. Like I pee more often than normal but not as much. And when I go I have this intense pain in my lower abdomen. Please help is there something wrong?