Mood swings do occur while pregnant, however it can also be because of pms. I know right before I would get my period I would be so moody which was one of the first indications to me that something was off because my period was almost due and I hadn't had any mood swings. I tested a couple days after it was due and got a positive and now at 6 weeks I find that i'm starting to get a little moody again.

If your period isn't due until the 23rd i'd wait until you miss it just to be sure. But if you really want you can test with first response 4 days before your period, but you may not get an accurate result. Good luck.

Before I found out I was pregnant, I was pretty normal most of the time. There were only a couple of times when I became totally irrational. I had one "moment" when I just wanted to be on my own and was ready to go for the throat of my bf! Found him later and we laughed about my mood, but didn't realise until a few days later that it was pregnancy mood swings!