Why is my period taboo?

Today at work, a co-worker called me out for being loud.  That typically doesn’t bother me. But instead of telling me to lower my voice, she was obnoxious and announced "You’re really loud!" while I was talking to a customer.  I was taken aback and took liberty of blaming nature.  "I’m a bit hormonal today," I told her. 

"Oh so I’m not a woman and wouldn’t know? I have hormones too."

I mentally raised an eyebrow at her snide remark and continued with "Well I’m on my period."

"Way to broadcast it to the world.  Why don’t you say it louder."

"I don’t mind telling people when I’m on my period. I’ll say it to any one.  It isn’t like it’s something I need to be quiet about."

"Look, I’m a woman too, and I’m just saying that you don’t need to broadcast it."

The conversation went on that way until she saw that I was getting upset, hormones notwithstanding.  But the whole thing got me thinking: Why is my period taboo?  Why is saying that I’m on my period equivalent to some people that I have diarrhea?  "Ew we didn’t need to know that?"  The story goes on.

My boss is rather intrusive with, on the whole, ridiculous remarks about a conversation he’s not a part of.  Needless to say, laughing at him is something we avoid since it furthers this behavior.  So I didn’t laugh at his gross remark about blowing up puppy dogs and said it wasn’t funny. 

"Well you’re no fun," he said.

My co-worker, while my back was turned no less, whispered loudly, "She’s not going to laugh.  She’s on her period."

I snapped back around and said, "You know, that’s for me to tell others." 

"Well you broadcasted it earlier while he was here so he must have heard it."

"He wouldn’t have heard it since he was in a meeting."  We looked at my boss who could see that this could get him in trouble and said indignantly "She didn’t need to tell me, I already knew." Whether it was true or not, it was a wise choice of words. 

"But still," my coworker went on, "you had already announced it, so it doesn’t matter who I tell. You’re being totally contradictory."  She went on about how I wasn’t treating her as if she was a woman and that I was just embarrassed.

I finally said, "It’s not about embarrassment, it’s about respect."

"Whatever." And she finally dropped the subject.  I stewed about the whole thing for a couple of minutes, but once I saw that it wasn’t going to come up again I let the whole thing go. 

I think what flustered me most about the whole ordeal was suddenly my period was an issue, and despite her claims that she wasn’t embarrassed easily, I was not convinced that she wasn’t ashamed on making it a public matter, then used that point against me to tell my boss.  But hell, it’s my period and only I get the right to tell people that I’m affected by it.  I wasn’t embarrassed that she told my boss. It was her manner of telling him: right behind me in a hushed tone, like I had the plague.  It was disrespectful to me as a peer, but not embarrassing.

Periods are nothing to be ashamed of.  It’s a natural biological process. And yes, it does affect my behavior to some extent, but I can get by on the whole without being "emotional". Sometimes I let hormones get the best of me but it’s no different than being angry since all emotions are hormonal, menstration notwithstanding. I don’t make any bones about when I’m on my period.  To me, it’s an expression of accepting my body for what it is, even the parts I don’t like.