How'd you find out about your rainbow baby?

I wanna know! :) we had a miscarriage in July and the few times that I might've been or was late on my period I try not to obsess but sometimes I think I do.. I have a fear that we won't know and I'll get drunk or smoke if I'm in the mood to then put out baby at risk. I didn't know I was pregnant until someone told me to test and then I lost the baby not long later (I did have some symptons but when everyone said I was pregnant I didn't think anything of it since A it was only girls from college B I thought my health was funky)