Should I be worried about a hematoma due to burst blood vessel in penis from accidental bending during sex?

Depends on duration. Most hematomas of the penis are due to traumatic sexual congress vs masturbation...Immediate evaluation is indicated as hematoma in this are can spread and leave residual problems with erections and may even be due to fracturaing of the lining of the corpus cavernosum.
No. If the hematoma happened during sex, it was probably just a minor blood vessel that broke or leaked. This would imply that the hematoma is not that large (< 1"), but may look awful--purple, black, green & yellow. It will heal all by itself over a couple of weeks. If you apply hot compresses, it will heal even faster. There is nothing else to do. This is just a freak occurrence.

Related Questions

Burst blood vessel in my penis can my girlfriend get infection of my blood?

Not likely. This could only happen if you had an infection which was transmissible through blood. This would most commonly be either syphilis or hiv. If you are concerned about these would strongly suggest that you be tested. Read more...
No relation. Risks of transmission of blood borne disease without true erosion through the skin are minimal if at all. Read more...