hcg levels

So i did my hcg levels this morning and it was @ 300!  the ARNP said my scheduled last period was 7/30/13 according to transfer date and stage of embryos.  she said for being this early that might mean i've got twins going but won't know for sure til i get my u/s on the 5th! yay!! im very fatigued, nauseated, cramping and breasts are very sore but i don't care!  this is what i was working for!