please read and comment any advice

Not sure what to think. Hubby and I have been TTC for 7 months now. I got a period on the 28th (last friday) it lasted through Saturday (normally my periods are 1-2 days). Then Saturday evening into Sunday morning I was wiping and it was almost clear like my period was gone. Sunday night I think or Monday morning I had wiped and there was blood but very light amount and polka dot looking not smeared but more spotted. I didn't think anything of it. But yesterday I was feeling nauseous and my friend said take a test you could be pregnant, I said but I got my period she said so I had got mine when I was pregnant. She had a period with her daughter in July and then had found out in August she was pregnant. She told doctor she was further along than July and ultrasound confirmed she had conceived in June but she had a period in July. I took a test yesterday but it was negative. I've read about if you didn't implant until the 12 days which lands right at your period you could still have a period or a small one cause your body didn't have enough time to tell it to not. I had taken a test 4 days before my period and that was negative. Could I still be getting negative results and be pregnant?