Do i have cancer?! Help!?

have an infection or something?

Im a tenager

I have had sex, but with one person and protected so im pretty sure its not an std

I have had lots of discharge that changes colour every once in a while, from greenish yellow, to grey, to currently white and thick.

I have horrible constipation lately, this was never a problem and lately its constant.

Sometimes i feel a sharp pain in my uterus or vagina that lasts a few seconds.

Before i took birth control bills i once had my period for a month straight but when it ended i just hoped it was because of it being someone new (about a year or two back then).

I have back pain and headaches. Im very tired al the time.

I have no energy.

Sex is painful.

When i pee i feel like i still have some left in me that wont come out.

Im so young.. Is this normal?