Mom to a daughter affected with PKU here.
I'm sorry your OB didn't immediately offer you a full generic screening from day 1 of you asking. Hopefully that was a miscommunication. I would recommend asking for it now, especially if finding out you and your husband are carriers for the same generic disorder (PKU or otherwise) would change your plans for continuing your pregnancy.
In regards to PKU specifically, if your husband is a carrier, then your baby has 25% chance of being affected. So, not very likely. However, of all the generic disorders out there, PKU isn't so bad, is totally manageable, and would still allow your child to grow, thrive, and live a totally normal life. There are many other disorders that can't say the same.