Don't blame it on my period

So, I get really bad mood swings to begin with and ontop of that I have a few mental disorders as well. Between the two, the week before my period is rough, but that doesn't always discredit what I get upset about. So this week I was getting frustrated with my boyfriend and we talked about it. But now I don't want to tell him I got my period because i don't want him to just brush off our conversation as I was just upset because of my period.