In need of advice please anyone experienced this before?

Abi

Hello so my LMP was July 16,2019 it last 8 days and i have a 29-31 day cycle. I had sex August 4,5&6 unprotected and August 10th i spotted pink when i wiped. My cycle is due in 2 days and i have none of my normal PMS symptoms only cramping once and a blue no sore breast or anything but i am nauseous here and there. Is it a possibility i am pregnant and if so how long should i wait to test?