Should I tell my long distance boyfriend I'm on my period? (Please answer)

So, this guy and I haven’t been dating long (about a month) but we’ve been friends for 6 months now. We pretty much tell each other everything. I get really moody and mad when I’m on my period and I’ve snapped at him before while I was on it. I honestly want to tell him but I don’t know if I should or how he will react. We have talked about a lot of personal things and he isn’t a baby about stuff but periods have never came up in discussion. I don’t want to keep making up excuses for being rude or really emotional. I just don’t want things to be awkward between us. Should I tell him and if yes, how do I tell him? And if your a guy how would you react if your girlfriend told you she was on her period?