Confused

I have so many different apps telling me different days of predicted ovulation. One says it was yesterday and some say 4 days from now but I’m in my fertile window according to most of them except one which says tomorrow begins my fertile window. Having said that. I’ve had sex (unprotected) the 10th,13th and then again last night. Is there even the slightest chance I can get pregnant? After a miscarriage in March, iv been iffy about trying again but I also want another baby.