Please help and read! Possible chemical pregnancy??

I got these positives well 3 positives on Wednesday. Then about 2 days later I got a first response rapid result, and it was negative. I tested the next morning with the FRRR and it was negative as well. I've been feeling really sick, and having weird cramps. Just been feeling different too, I'm confused I'm not bleeding. Could it still be a chemical? I took the positive tests at 11 dpo. so I'm now 16 dpo, I haven't tested since about 12-13 dpo. Not really sure what to do... help... xxx