Am Vanessa 18 Years Of Age. I Had My Period

Am Vanessa 18 years of age. I had my period on the 29th of July.and my period last 5 days.on the 3rd of August i was in my safe period and i had unprotected sex but he ddnt come in me.i took pill the next day.then on 9th August the results for amdmissions into the University were out.i became scared ..stressed .sad when i saw my results.the next day i started bleeding.i did not understand why.and the bleeding lasted for 5 days as my period last..on the 13th i had sex again but with Protection.i want to know if the bleeding i had on the 9th was because of stress ..and will it affect when my next period is supposed to come?