I have a 99 Safari van that I think the heater core is bad ?

What is your question?

I was driving and started to smell coolant and then noticed there was coolant on the passenger floor and it wasn't really a lot but it just stopped so I parked it but drove it the next day and there isn't any more leaking like it just stopped I also have heat and it is blowing hot heat and it's not over heating so I'm confused so I bought a heater core anyways it cost me $100 but i don't know if I should replace it if it isnt neccessary so my question Is has anyone else heard of this or has it happen to anybody were the heater core leaked and then just stops leaking with no over heating and I also have hot heat still ???

How long has your 1999 Chevrolet Astro had this problem?

Couple days