Oops!

I was clearing out our guest room to convert it into a nursery and I lifted a storage tub for a few seconds that was 40 or 50 lbs. I felt immediate pressure in my lower abdomen so I put the tub down. Baby is still moving around and I only feel a slight pain, nothing else is going on so I don't think I need to call the OB unless anything worsens. I'm 22 weeks and healthy pregnancy so far. But I'm resting now with my feet elevated and drinking water and worrying anyway...