Ovulation and Breastfeeding

I am breastfeeding (my baby is 8 months and also eats solids). My period has been very irregular which I know is normal. I haven’t had one for a couple months. I honestly want another baby so that my kids are close in age.

About a week ago I felt some pain. I decided to take an opk just because I was concerned if something was wrong and I was just curious. It happened to not only be positive but the test line was significantly darker.

My questions are:

Has anyone experience this?

How accurate could this be since I haven’t really had a period in a month or two (if that’s even what it was)?

When you get a surge like that, is that when you are supposed to start having sex?

Thanks ladies!