when can i take a pregnancy test??

I recently had a miscarriage in October. I have very irregular cycles, varying from 28-32 days, and I'm not sure if my miscarriage has caused more irregularities. I did start my cycle again 1 month post m/c. so I've been using an ovulation kit daily, and today, cycle day 19, I finally got a +yes. I'm not sure how soon I can take a pregnancy test. because I'm not sure when my next cycle will start.

last February I had a stillborn, delivered at 37 weeks, we waited the recommended 6 months before trying again, and then had a miscarriage. we are really hopefully and praying to get our rainbow baby. 💗🌈👶