Some questions regarding LH testing

TW: Mention of Pregnacy loss

I had some questions regarding LH testing. I unfortunately had a miscarriage last July. We had not been trying and we had only just found out before I had that loss. We decided we wanted to start trying bit have had issues because my period still has not returned. I've been to a doctor and they are running tests, and hopefully we will soon know why. But regarding LH strips, how should you go about them. Is there a specific time that your should be testing (what I've googled is any time between 10am-8pm and a surge last 4-6 hours and typically is in the afternoon/night) I also wasn't sure if there was outside things that could impact your LH surges. I've not had a surge since August and finally am in a surge and wasn't sure if it was real or not. I was googling about foods and alcohol and as far as I read it doesn't matter.. also when should you BD? As soon as the test line is darker than the control? Or do you need to wait to see if it gets darker?