Help please

Girls help me!! About 2 weeks agoish me and my boyfriend had unprotected sex and he finished inside me...then the next week I was in work and I got super super nauseous on the Monday and this continued right through to the Thursday and then the next week came around (start of this week) Monday to be precise I had a headache that lasted 4 days and an awful backache...my period is due today but on Tuesday I started to spot no cramping or anything...it’s very very light and pinkish colour sometimes mixed with brown discharge (gross I know) I’ve heard implantation can occur when AF is due so I’m confused is this my period or implantation? And when would be a good time to take a test!?!?