I met up with my girlfriend last weekend, but I think she didn’t get it. She was planning something more romantic, but I pulled back because I’m on my period. Should I tell her openly or are these things just not discussed? If you were in my shoes, would you explain it clearly, or would you let her figure it out?
I think it would have been better if you had said something, after all, there would be no need for doubt. A light explanation like, ‘I’m a bit uncomfortable right now, could we talk later?’ would have sufficed. No one else is obligated to understand in your place.
If you’d just say it openly, you’d actually feel much more comfortable. I don’t think these things are shameful or taboo. Saying, ‘I’m on my period, so it’s a bit difficult for me to do some things right now’ is very natural.
The stress you feel when pulling yourself back is very familiar to me as well. It really gives you the feeling that you’re disappointing the other person. But honestly, this is not your fault 
But let me ask you something, why do you think your boyfriend didn’t understand? I mean, some guys expect you to bring it up directly, but maybe he already understood and didn’t want to mess things up? I think you should investigate a bit more 
I personally don’t find it very right to discuss these topics with someone you’re in a relationship with. I mean, sharing such intimate things before marriage, in my opinion, slightly undermines privacy. Shouldn’t they understand that? 
This kind of communication problem can lead to more issues in the future. Menstrual periods are something that should be discussed due to their physical and emotional effects. Open communication creates a healthy relationship, I think you should say it without hesitation 
Let me update you: Actually, that day I was a bit quiet, and they asked, ‘Is something wrong?’ I felt for a moment that I wasn’t enough. That’s why I didn’t bring it up at all; maybe I exaggerated the situation.
As a man, I can say that most of the time we can’t think too much about these periods. But if you say it clearly, I don’t think you’ll get a bad reaction. If he’s planning romance, his intentions are good; it’s just a matter of misunderstanding 
But the need to hide this menstrual period is already coming from societal pressure. If you can’t talk about this comfortably with your partner, there might be other things that will make you uncomfortable too. This is your body and your boundaries; there’s nothing to be ashamed of