should I give my ex a second chance? I'm 22M, and I need advice

Three years ago, my girlfriend and I broke up because we had frequent fights. We used to break up and get back together often. But during one of our usual breakups, about 7 days later, I found out she was chatting with another guy. She said he was just a friend.

I stopped talking to her after that. A month later, I found out she was in a relationship with him. They were together for about 3 months before breaking up. After they broke up, she came back to me and begged for another chance, but I didn’t accept her.

A year passed, and she got into another relationship, which lasted 6 months. After that breakup, she came back to me again, begging for one last chance.

For the past 3 years, every couple of months she comes back, begging me to take her back. She’s had two relationships since we broke up, both short (around 6 months). I don’t think she slept with them, but I’m not sure. I’m confused. Should I take her back or not?