First of all, I think you should go with your gut instincts and take what MDs say with a VERY LARGE grain of salt. If I had listened to them I would be dead. They (all, not just one) totally misdiagnosed ME, but that's another story. You have to be proactive and make sure that you are proactive working WITH the doctors, not just doing what they say and your health and your baby's health will be much better for it.
Suggestions:
Do not give a child any shots until they are 6 - 8 months of age. Then, go slow. 3 or 4 shots at a time maximum should be fine by that point. If it's a combined shot, just do one, then come back in a couple of months. Do it on YOUR time schedule, not the doctor's. A lot of children now have screwed up immune systems now because too many shots too soon. My children all have very healthy immune systems (aren't allergic and never had antibiotics, either).
Thimerosol (may not be correct spelling) is what used to be used in the Hepatitis B shot and in the MMR shot. The doctors have denied that mercury poisoning occured in kids where Thimerosol has been given, however, there are a lot of parents who say that their child was NOT autistic until after the shot was given to their 2 year old child. It has been proven outside of allopathic (MD vs ND) doctor circles that Thimerosol DID cause autism. (I have a friend who's son is severely autistic and says he has all of the symptoms of mercury poisoning) - but no one will admit to anything. NOW, the medical establishment has (without claiming any responsibility for this) turned around and taken all of the mercury out of the shots. So, you're in luck. You don't have to worry about it any more. However, I would NOT give my own child any shots until they were a little older, especially since I was breastfeeding. I also REFUSED to give my daughters the Hepatitus B shot when they were born, for 2 reasons. Why are you giving a little child a shot that was just born? They don't even have their own immune system yet, for goodness sake. 2nd, there was thimerosol in the shots at the time. Plus I'm not a drug user or addict, neither is my husband. We're both monogamous. The drug companies are eager to sell drugs, the faster the better. I think that's the push for having extra vaccines that really aren't needed or to push for more, ealier.
My advice to you is, take the shots, but go slow. I did things on a much later time schedule than the doctors suggested. In fact because I did that, the children ended up (all 3) with less shots than if I had given them when suggested. I would not give any of my children shots before 6 or 8 months of age. I also spaced them out so they didn't get more than 2 or 3 vaccines at a time. By the time they were 2 or 3 they had all of their shots, but on what I thought was healthy, not on the sped up timetable the doctors gave. 19 years ago when my son was born, the timetable was much different, much healthier than it is now. First shots were not started then until 6 - 8 month. To me, that is more reasonable. I think it was a year before I gave my daughters her first shots, but again, I was breastfeeding. Breast milk has your immunity built into it.