Scared of miscarrying again.

Em

I've yet to have a living child. I've had 3 early miscarriages. We had sex last night without thinking about where I was currently at in my cycle... took an opk and it was positive. I'm sickeningly terrified... yes the last time I tried baby aspirin and folic acid... miscarried again though..m what do I do...? I just need some kind of advice...