Need Some Help For Calf Pain

I have been training for several months for a half marathon scheduled for April 18. In the past, I have had problems with my left calf (calf heart attack) and had to learn to rehabilitate it. Fast forward 2 years and I have been doing great with my half marathon training. I wear compression sleeves and ramp up slowly. Yesterday, for my 13 mile run, I decided to run 6 miles on the road and 7 miles on the trails in a hilly environment. That is first time I have run on trails in about 6 years. With about 2 miles to go my left calf really tightened up and was painful in the same spot I had my calf heart attack. This time though I did not feel the pull or pop.

Now, I am not sure how to treat this with only 3 weeks to go until the half marathon. The half marathon will be on a flat surface. I don't know whether to see someone or even if I am going to be able to run the half marathon. What are your thoughts? Thank you in advance!