I realize you posted this yesterday but if I were you I would have cancelled the appointment until you have fully researched this issue... you can always decide to vaccinate later.
I can't help you with delayed schedules as after a yr of researching we decided not to vax at all.
As far as mumps... for one the 1st MMR dose is not given until 12-15 months so that will not be one for the 4 month visit.
Plus a huge amount of people who contracted mumps were vaccinated against it so that just proves that immunity is questionable as far as effectiveness and how long it lasts. The MMR vax is also one of the most dangerous ones, so read up on it before that 1 yr or 15 month old well baby visit.
There is a ton of info out there, I started by researching the facts about each vaccine and the diseases they are intended to prevent. Then I looked more into the vax controversy once I knew statistics. 2 sites that sealed the deal for me were the CDC (center for disease control) and VAERS (vaccine adverse event reporting system) both provided by our government BUT had I started there I would have probably came to a different conclusion as they of course promote fully vaccinating.
Good luck on this journey, no matter what you decide the most important thing is to be informed before you do anything!!!
- mama to Denae 5, Nathan 3, Jayden 18 mos and