Chemical pregnancy? Confused.

Susan

So I had my period from 26th May. On the 5th June got very positive tests but before period I had negative test results. Doctor seemed confused by this but said wait 3 weeks and call them back. Tested every morning with positive results. Having slight twinges and felt really tired Saturday and Sunday. I haven't got my hopes up because I had my period (was definitely a period not implantation bleeding?) but so confused. It's now been a week and a half since my period and positive tests. Is it chemical or not? Anyone ever experienced this before?

PS I only found out I had a positive pregnancy test because I took an ovulation test to start trying. Came up positive which I did suspect was too early so took pregnancy test and Boom BFP.