OPK Results

Cara
Hello everyone. We are first month TTC and I've been doing OPK since CD13 without any second line at all.  On CD19 today and got this. I don't think it's positive yet but does it mean it will be if I keep testing over the next 12 hours? And if so, when is the best time to have sex? We just did it this morning before I got this so should we do tonight and tomorrow? Any advice is so gratefully received!