And I have no problem helping a lady with those unfortunate cramps. I’m there to lend a hand (at the very least). 
I’d say a quick e-mail or note to an HR person simply stating:
“It makes for an uncomfortable work environment when so-and-so speaks openly and loudly about her menstral cycles” will do wonders.
If you work for a legit company HR will definately do something about it. They are obligated to and usually want to nip it in the bud before it goes over their head and becomes an issue they failed to address.
Because blood is a bodily fluid that can transfer pathogens. I always use a love glove, but still, the odds are greater with someone actively bleeding on you that something could be transmitted. It’s a small risk in general, given that I don’t tend to date women who count their lovers in the hundreds, but it’s there.
How gentlemanly of you!
Noooooooo don’t do that - it will escalate and cause very bad office tension. To nip anything in the bud, you (the person with the issue) needs to talk sensitively to the person who is offending you.