ovulation test.

Renée
Hello my name is Renée and I'm 18 and I'm TTC #1. I'm very confused on the first response ovulation test. I took one on the 8th and it says I was ovulation (and on top of that I have been having tender breasts and slightly cramping.) I take another ovulation test 2-3days later and it says I'm not ovulating. And when I found out I was ovulating me and my partner had unprotected sex.. So im not sure what that means.. Help?