My Gf Had Periods On 5may And I Sex With

My gf had periods on 5may and i sex with her on 12 may. Because of leakage of codom may be small quantity of serum released inside her vagina. After 10 hours she took unwanted 72. I was done pregnancy test on 24 may with preganews that was negative. Agian i test on 5 june that was again negative. Today is 8 june nd no periods come. I should i do now? So worried.