Rhogam shot opinions

So my blood type is A- and was told early on in my pregnancy that at 28 weeks as well as postpartum, I would be given the Rhogam injection. I didn't think much of it but since my next appointment in a few weeks is the appointment they are planning to give me this injection, I decided to do some research. My husband has the same A- blood type as me which means we will not conceive a child with a + blood type. I am considering opting out of this injection, at least at 28 weeks as it seems unnecessary. If for some crazy reason my baby comes out with a + blood type (so unlikely), I would obviously accept the injection within 72 hours of the birth. What are your opinions!?