Spotting and unplanned u/s @ 13w5d

Well, it has been an interesting day.  After being clean as a whistle all this pregnancy, I had a some unusual light tan spotting yesterday and this morning I had some dark spotting, which prompted me to call my OB.  She told me to come in for an u/s.  I drove into the city and waited a bit to be squeezed in. 

Thankfully, the u/s was perfect, which was a huge relief.  Baby A is measuring right on track and Baby B is 14w and was literally boxing the air while she tried to scan him/her, it was hysterical (so much for cricket).  They both have heartrates of 160 BPM and are measuring ~8 cm/ea. (so big!).  They also did an exam and my cervix is completely closed.  They aren't sure where the spotting is from.  It is most likely from me weaning off my hormones.  So I'm to take it easy (no heavy lifting, exercise, sex, etc.) and hopefully it will just go away on its own.  Only two more weeks until we go back again, and I'm of course anxious to find out what we are having, hopeful that we can find out w/our extended level 1 @ 16w and not have to wait for the anatomy scan/level 2 @ 20w.  So excited!