15 positive tests?

Ok so I have taken about 15 tests and all positive. I'm only 12 dpo and I keep reading stories of chemical pregnancies so my question at this point is when does a chemical pregnancy stop being a concern. I've never heard of it but my son is 10. Been a while. I have an apt on the 23rd so I wanna be excited but I'm afraid. Don't know when it's safe to say I'm actually pregnant.