A little nervous

So I stupidly had unprotected sex almost a month ago. I haven't missed my period because I'm not supposed to get it yet, but I'm a little freaked out. I wasn't fertile when we had sex and he pulled out but there's always that chance. Also, about 4-5 days after I was then fertile. I am now cramping a lot and very tired. But I'm supposed to get my period in just a few days and I think this pain and fatigue could be coming from my cyst that I have on my ovary and my period?