what the heck is going on !

So I was going on 6 days late (which is never normal for me) so I went to the doctor last Friday and there test said negative but they seem to think I am, he said that if I gat a positive to call and if I keep getting negatives in a week to call and schedule blood work to take it easy and be careful if I start having horrible pains, or bleeding bad go to the er well now I woke up to bleeding not super light, but not super dark, not heavy but it's definitely there, and I wasn't having much cramps or much pain with periods like I normally have, I went off an on for 4 days then I had sex an started spotting, what is going on???? what are your opinions? Could I still be pregnant?