RH+ mamas with Reactive Coombs tests?

[Eleonora]

I understand the point of the Indirect Coombs test is to determine if there is going to be RH factor incompatibility between an RH Negative mom and RH Positive baby. However my blood type is B+ (so RH positive) so my first question is why do RH positive moms even have to have the Indirect Coombs test? But then the weird thing is I have had it numerous times and about 4 times in my first pregnancy it came out with ambiguous positive/reactive results and only once was a clear negative. Now again in my second pregnancy, it is again showing a positive. Does this happen to other RH+ people and what is the explanation? (My doctor was very vague and just wanted me to test again and everything I google about it relates to RH negative moms.) Any thoughts?