Modify workout for injury

lagcrg

I lost 17 pounds since starting MFP in Sept. 2011...that was from watching cals and getting moving through Zumba, but recently I added 30DS. When I started 30 DS I rested in between days, but this week I started doing it every day and as of Wed. one of my shins started hurting, especially during cardio(jumping jack/butt kicks)..Today I wanted to still follow through with doing the workout but had to modify the cardio spots...I am wanting to know if that is okay?? I was able to do some jumping jacks just slower and for jump rope and but kicks I did a light impact jog in place, but my shin is now aching again..What do you think?