ttc or are we?

Gabby
So, I have a daughter from a previous relationship, she's 10 (11 soon) and is desperate for a baby brother or sister. I'm in a relationship with an amazing man who's taken on my daughter as his own and we're a lovely wee unit (she's not seeing her sperm donor father at all).
When I first got together with my boyfriend he was adamant he didn't want children, and although I'm the broodiest person ever, was happy with that cause I have my daughter. As we'd agreed there would be no children, I suggested I get sterilised because I don't like taking the pill and the side effects it gives me. 
This obviously shook something up inside my boyfriend and he's now decided that he would like a wee baba, which I'm pleased about and I know my daughter will be delighted if it happens (obviously not saying anything unless it happens).
Reason for my post is, when we spoke about it the other night, we decided that I would come off the pill, and we'd just see what happens. Not actively try, but not prevent. So now I'm left wondering whether we should properly track etc, or indeed let nature take its course! 🙈🙈 sorry for ramblings, getting my thoughts out my head as we agreed it's best not to tell friends/family for now.
Should I push for actively trying??