congrats on the preg!
the stretching kind of pain is normal. everything is growing outwards and your internal organs need to shove over. i had them with DS, and the round ligament was what gave me the $h!ts in the 1st tri. this time round it's as beema said "all stretched out" the joys of your uterus growing (i think) its 500X the size it is pre-preg in nine months!