Your frequency will definitely increase (with possible leakage) as the baby grows and pushes on your pouch.  I was definitely going to the bathroom much more in the last couple months.  I took Unisom to sleep so I wasn't waking with every urge to go to the bathroom.  I never did have leakage though.  The only time I ever had leakage was when my pouchitis wasn't controlled.  Keep that in mind too as pouchitis is common during pregnancy.  If your GI thinks your leakage is due to pouchitis, a quick round of antibiotics might help you out to make it a more comfortable last couple months.