back ache and discomfort after heart cath

Had a cardiac cath 3 days ago.  I am doing very well, as no swelling and almost no bruise, but I have a low back ache, and I am pretty much uncomfortable deep in my gut, front and back, below my waist.  It almost feels like menstrual cramps, (but I am way too old for that.)  Also leg has general aches that come and go.  Gets better when I lay down.  Extended sitting or walking seems to make the aches worse.  Only laying down makes it better.  Can anyone tell me if they have had similar discomfort, how long it lasted, and (other than bed rest) were you able to get rid of the ache?  I REALLY need to get back to work. (Work requires extended sitting at a computer, I had no idea simple sitting could cause me trouble.)