My ex boyfriend gave me money, 7 months later he field bankrupt ... Can they now come after me for the money? He said they are coming after me

That depends on whether it was a gift or a loan.  If it was a gift, then yes the Trustee can sue you to recover the amount given to you if your ex was insolvent at the time of the gift. If it was a loan, then it's a little less likely, but if your ex did not properly list and exempt the rights to receive on the loan, then you could be sued for that as well.   It also depends on how much money is involved, and you haven't disclosed that.