Every woman is different, but the majority of us see some gain/stall at some point in our cycles. It's annoying, but if you know when to expect it then it's not such a big deal.
I find that I'm up a pound or two just before I get my period and once it hits those extra pounds slowly taper off.
When I was losing weight, I would sometimes stall just before my period hit and the get a nice couple pound drop during and after it
So stick to it and the weight will come off!