ok i had sex on january 12th and accordin to an ovulation calculator i was ovulating. while getting ready to use protection the tip of the penis was rubbing against the vagina. i did use a condom with the actual sex tho. well the period that i was expecting came on on the 19th but lasted a few hrs. i did have cramps all the symptoms for menstruation was there but nooo bleeding. its the 23rd now and i still have a headache and cramps. could i be pregnant?