Yes it can happen , it can be a side effect. It happened with one I was taking, I didn't last that long , I called my doctor said couldn't do it any longer. He said sometimes it takes some getting used to. I waited another 5 days (10 days in all) . He changed my prescription again. Good luck with yours maybe it's just taking a little longer. But I would definitely talk to my doctor. I had other side effects too.