Wah, this is quite common actually, a few of us had the same thing during pregnancy, especially around second trimester when blood volume increases and hormones are all over the place, but definitely best to mention it to your doctor or midwife at your next checkup just to be safe ya. Some of my mum friends said theirs went away after a while, but since you're first time mommy and every pregnancy is different, better get it checked out so you can have peace of mind and know exactly what's happening with your body.