So, had my regular OB appointment today and asked about this. She checked vaginally with her fingers (felt very good), and sent me for a transvaginal US just to be sure. Exactly at 3cm at 21 weeks (well, 3.01 - so they report as bigger than 3??), but no funneling or anything. They are not planning to recheck, unless they are other issues. No restrictions. This is a very good university hospital... Should I ask for a recheck anyway at my next check up in 4 weeks, and keep it easy in the meantime (legs up while not at work, no long walks etc.)?