I have a suspicion that my boyfriend is cheating

so I started dating my boyfriend about two months ago, we met on tinder. he's been really great to me so far but my best friend and I noticed something.. in the past few days, he's been followed on Instagram by some random girls that are from the area but not from HIS area, and they seem very much like tinder girls. I know that sounds crazy, but we've done some investigating and some things seem pretty off. there's a lot more details that I'm leaving out but I have reason to be suspicious. I completely deleted my tinder account so I have no way to check whether or not my boyfriend still has his account. I don't really know what to do in this situation... girls, help me out??