help please

Benjibellamommy
Hadn't had a period since I had my son back in June just revived my first period on September 27 me and s/o had sex on sep 15 and had an accident with. Condom we also had sex sept 21 and 25 using the pull out method but he pulls out a little before time .. my question is if the incident on 15 would of gotten me pregnant my period wouldn't have came in the 27 right ? I had a blood test done on the 27 and it was negative 
I still have another blood test pending for hcg quant should I take it now or wait a little longer