Positive OPK? When to time sex??

Hi guys! I took a break (well, started taking it easy) from TTC to get my cycle back on track (I have low progesterone).

I also have a short luteal phase, and am pretty sure Ive been flushing out my fertilized eggs since October :(

Anyway. I started progesterone last month and took an OPK today. This is what I got. Is it a TRUE positive? When should I time sex?

Usually I don’t get a positive looking OPK till CD 17/18, but today is CD 13... maybe my body is doing its job now? Lol.

Have a great night and thanks for any input. You guys are amazing.