Pain in hamstring with movements, no swelling no bruising, pain started 30 hours after workout but doesn't feel like DOMS. Blood clot?

Exercise related. You worked out. Then you noted pain in hamstrings. This most likely represents sore muscles from the workout. If you are otherwise healthy and 18 years old? I would stretch the area of soreness. You note no pain at rest no swelling... Thus unlikely a blood clot. If you are short of breath, recently on birth control then see doctor immediately as that would be concern for clot.