New to the OPK so help me out.

I am currently trying for #3. Just had my IUD removed early this month so I was curious and got these cheapies.

So I have so far always had a line and I KNOW it’s negative but my question is does this mean I’m getting close since it continues to get darker? I also have found mine are darker in the AM which is different from what others say.

I don’t technically know if I’m in my window because I think my AF was due to having the IUD removed but we have been BDing just in case.

I would love to make this quick (it was in the past) since I’m 35 and a teacher I want to time it towards the end of the school year. Any help or insight would be appreciated. Baby dust to all!