I am not sure who the father of my son is. Is it possible to tell the father of the baby simply by knowing blood types and Rh factors of myself and the potential fathers?

My wife and I had our first child last July. Until about 3 months ago, she was unable to reach orgasm at all. Of late, she has very small one's, but they don't seem to be getting much better. Prior to having the baby, she had strong, very quick (3-5 minutes) orgasms 90% of the time. I know the stress of being at work rather than home with the baby could play a part in this. Is this common and is there a way to mitigate the problem? 

If one has a long-term partner and neither AIDS nor any other STD is a concern, is there any medical reason not to perform cunnilingus on a menstruating woman? My significant other is particularly horny during her period and would love cunnilingus at this time. I am willing but curious.

I'm a 19-year-old female. I had my right ovary removed (oophorectomy) three years ago due to a very large ovarian cyst. I was assured by my gynecologist that I'm still capable of bearing children but wasn't informed thoroughly of all of the pros and cons in regards to this type of operation (e.g., can the estrogen loss have any negative physical affects?). If you could shed some light on this matter, it would be greatly appreciated. Thanks.