So last month I see my. . June 6, 2017 and my period is irregular the fertility app show my fertile days was from the 6/18-6/23 I had sex from the 6/19-6/23 I seen my period July 5 it's now July 11 2 weeks after I had sex last night I caught a slight headache along with little cramping and I woke up this morning sick to my stomach nauseous and throwing could I be pregnant