Chemical Pregnancy

I am scared to death and can not stop Googling! Last month my DH & I were shocked at a positive pregnancy test - we weren't even trying! I had a miscarriage at 5 weeks and we were devastated. My doctor called it a chemical pregnancy. At the time, I found out I was Rh- and got a Rhogam shot about 4 days after my miscarriage. We started trying again this month - I am 15dpo today and have gotten multiple BFP's!! My anxiety is through the roof which I know is not good. I am OBSESSING over having another CP. If I take HPT's for the next few weeks and the lines get darker will I know I am "safe" from a CP? I am FREAKING OUT!! Has the Rhogam shot protected me from another CP?? What are the chances of having back to back CP's?