It's a boy! and new baby anxiety?

On Friday last week we had our BIG ultrasound and found out that we are having another baby boy!  We are super excited that Frankie is going to have a little buddy to grow up with.  I think that Frank really thought we were having a little girl, so he was absolutely THRILLED when the ultrasound tech told us it was a boy.  Everything looked great at the ultrasound, but they want to do another one in 4 weeks so that they can get a better measurement of the baby's heart.  It will be nice to be able to confirm that the baby is still, in fact, a boy.  We are pretty close to deciding on the name, but we are not 100% sure yet.  

In other news..in the last few weeks, Frankie has really been clingy.  He cries almost every day that I drop him off at day care, and he often cries when I put him to sleep at night.  Yesterday he did not take a nap at day care, which is VERY unusual for him.  He has also been having some pretty massive temper tantrums lately, and I am wondering if all of these issues are manifesting as a result of his anxiety about the new baby.  I talked to his teachers about it briefly this week, and they said it is very common for toddlers to have a strong reaction to a new pregnancy.  It breaks my heart that he is already acting this way, and I hope that it is a phase and not a sign of what's to come once the new baby arrives.