I hit my shin very hard, i have bruising two small cuts. feels better elevated and with tight sock.. could it be hairline fracture ? i'm on levothyroxin for hypothyroidism and hemophilia factor 8... should i be worried?

Could be fx: It could be a slight fracture depending on how hard you hit it i wouldn't be "worried" but i would suggest an xray to evaluate the possibility of a rracture so get an exam and xray of the tibia.

Factor 8?: Go see your hematologist. Best of luck, though it could be trauma and a a hairline fx as you suggest, it would be wise to see your hematologist to assess your clotting mechanisms are working as they should!