Rainbow baby after miscarriage? in Life of a cat mom

2 years ago I miscarried a baby that I really wanted. I never even got to hear the heartbeat. I assumed that where I am 37 that I would never get pregnant again. I just took a pregnancy test and it turned positive. I am really worried. I am going to go find out tomorrow how far along I am and what medications I need to quit for the safety of the baby. I am worried and scared.. any advice?