Moving on

I was dating my ex for 2 years and we lived together, he had a kid and I was apart of their life as well. I had to move for work, I found out he was texting others and it kind of went down hill from there. Even on a dating site. Not sure if this was before or after we broke up. I met someone almost a month later and we’ve been together for 4 months now. I feel like my feelings are genuine I really care about this person, I’m not dealing w my ex at all But is it too soon to be moving on to something so serious?