Help me please!!!!!!!

On the 13th of december glow says that was my ovulation day. I kind of had sex that day but not really... it was my third time trying sex and i was still experiencing pain. He really didnt even get it in all the way begore we stopped. Even though he didnt cum we still checked the condom just to be cautious and it hadnt broken..... im sex days late for my first predicted period. The second predicted period said it was supposed to come yesterday. I also have had a cold for about 3 or 4 weeks... ive heard that sickness can affect your period. Im 17 years old and im scared... what should I do? Why do you think my period hasnt came?