Injured or Stronger?

3 sets of
30 hands off the deck pushups
15 rows at weight of 12

followed by curls to failure and press downs to failure

This is the same workout I've been doing for the last few weeks every Monday, Wednesday, and Thursday.  The way I am judging my progress is by how far I can get in the last set before I have to stop or slow down.  Right now I can get to the 3rd set around 27 reps before I have to slow down.  I might have to start mixing this workout up with different more difficult pushups like dive bombers.

My legs still feel really weird.  I'm not sure if I'm sore from a workout or injured.  I can do every kind of stretch I can think of and it doesn't seem to make anything hurt.  I just feel really stiff.  I plan on doing another leg workout tomorrow I'll be sure to pay attention if my legs start protesting too much.  Nothing throws a wrench in training gains like an injury.  The whole reason I spend almost 20 minutes warming up is to avoid injury.  Heck I warm up to warm up.