Worry about chemical?

This is my first pregnancy and I'm soo excited!  I found out Friday morning at 9 dpo and haven't even told my hubby yet because I ordered a onesie that I am going to announce with, which will hopefully be Tuesday .  Anyhow, I keep testing every day and keep worrying about it becoming a chemical pregnancy.  My line seems to be getting darker, but I've had cramps on and off the past few days and I found out soo early.  At what point do you think you are "safe" from it being chemical?  Anyone else have this worry?

Danielle