Could I be pregnant??

Ok so I’m freaked out and just need to know, I had sex (unprotected) but he didn’t cum inside me on June 12th (day 15 of my cycle, also in my fertile window) and then got my period June 25-29 (typical) and I’m two days late this month. I’m almost never late. My other period app says I’m 4 days late and I’m scared. Is there any chance I could be pregnant?

Also, at what point should I start being worried about pregnancy if I shouldn’t Be yet?