when do I take a test or know what to do?

So I have been ttc for a few weeks now. I got off my depo shot and is cleared out of my system. It caused a lot of abnormal bleeding so i was getting back into routine. So going great and the past few days I've been REALLY ttc. So when do I take a test? It says I'll start af in a few days so what do I do? I think I'm lost when it comes to all this. please help!! What's the best way to go about all this 😅😅😅 So can I get pregnant ???