Tip toed for 1 min, now very intensive pain in left calf for 3 days. can straighten foot but not flex it. nothing to see on leg. what is it?

Strain: This suggests a strain type problem with probable microtears in the calf. Phlebitis doesn't appear likely. The muscle healing takes about a week, so avoid further stress on your calf. Warm applications,and antiinflammatories like Advil, (ibuprofen)if you can take them, May also help. See your physician if symptoms persist or worsen or if leg swelling occurs.