Lost as to when to use estrogen cream, and how

I have wanted to restart using Estrogen cream and I am unsure of if I'm using it correctly.

Also I wanted to start when I wasn't on my period (I imagine the period itself might just flush out the medicine when I'm bleeding heavily, but maybe that's silly). I can't seem to stop bleeding, but it's calmed down some,so I might start now and hope it's fine?

I am post much looking for reassurance on how to do it properly/ at a good time.

I also don't know how long to wait before sex is okay/ how timing with that works.

I get nervous about taking any medication and I keep worrying I remembered the instructions wrong or misunderstood the directions when reading them. I'm fairly sure I wasn't doing it correctly before.