how many dpo should you test?

Hi ladies, I've got one 8 month old daughter and we've started to try again for baby #2. But I've forgotten all the ins and outs haha. According to my Ovia app, I ovulated around the 17-18 of this month (9-10 days ago) I won't lie, anxiousness got the better of me and for the past 3 days including today I've taken pregnancy tests and they've been BFN's. I'm not due for my period until the 3rd of May. (I know, I'm testing so early but I just cannot help it)
I guess my question is.. am I out of the game this month? Or am I testing way too soon? When does one usually have enough HCG in their urine to show even the faintest positive? It's only our first month trying so I know I should be patient lol.
Also I should mention that last time I was TTC I was using opk's to help me, so right now I'm solely relying on the app until the new opk's that I ordered arrive. So who knows, i could have earlier or later.