Baby daddy left me

So long story short my baby daddy left me and our two year old 2 months ago. he said he wasnt in love w me for a long time after being together for 5 years he said he found me unattractive bc i gained some weight and the bridge is burned never getting back together. My bff has a guy best friend we met started talking n we fell into place feels like i known him my whole life. Long story short we’re getting to know each other better i sleep over we talk about us, he has no kids, talking about he wants kids w me calls me his wife and already wants me to move in with him. We have 3 weeks talking. As a single mom is it very hard, he makes me feel comfortable he doesnt care about my mommy body said he loves it and doesnt want anything changed. My point is how soon is too soon to move in with him, he has his own two bedroom apartment and he always tells me me and the baby have a place at his house. He treats my son soo good. Anyways how soon is too soon, anything helps any advice thank you guys ❤️