Anyone have a harder time...

On days when baby is more active???  I'm 31 weeks and baby has been very active since about 18 weeks, but somedays even more than others.  I find I have more pain and get tired more easily, not to mention more BH contractions when baby is moving around a lot.  Am I the only one or is this normal?  Like days when she moves like crazy I need to rest a lot to counteract.