Why am I not having my spell?

Well i haven't had my term in 4 months but every assessment i take say I'm not pregnant and the doctor said i wasn't but i am scared to run back what else could form me not have it? I am not on no birth control or nil like that someone please give a hand i am despreat and very scared
Answers:

Tampons?

There are several reason that come to mind for missing a period.

Rapid cargo gain or loss or increased exercise such as running. Sometimes major stress surrounded by your life will stop a term or extend it for longer than normal. Excessive worrying, fatigue, diets, unsullied job, spontaneous bills, etc.

It is common for women to miss period for no discernible reason. Some women never hold regular periods, skipping months at a time.

Don't verbs about it, digit out what is going on in your life that might be cause the lack of period and see if you can fix it.

Can a 15 year old womanly have low blood pressure?

how elderly are you? perhaps your body isnt used to have sex and is messing up your menstural cycle.

I missed my period this month and took plentiful tests that come back negativewhat give?!?

by stressing and worrying about it will kind it not come.
and maybe acquire some medication to regulate your period?

i've missed my time of year for two weeks already and im worried too.

[EDIT] I dont know, me and my bf only have dry sex, never had intercourse up to that time. i went to the doctor and he did two test for me and i did another test something like a week later at a counsellor's place... adjectives were distrustful. and im still waiting for my period.

[EDIT] Oh Im Pinkwhite by the track. I changed my avatar and name ahead of time.

For those who have have a D&C?

Not sure your age, but there is a condition call Polycystic Ovarian Syndrome (PCOS) that can cause your period to stop or be irregular. With that, you can develop cysts on the ovaries, whacky hormone levels, - it's sort of complicated to explain. I'm assuming your doctor have checked you for tumors, etc. that could cause a interval to stop. When I was younger, recurrently mine would stop if I went through something intensely stressful. There are a lot of things that could be going on, so verbs to bring it to your doctor's attention.