Women does not have to always bleed to be on their period so relax if a test is negative that you taken 6 of because you're worried of being pregnant. Pregnancy does not always take your period in fact you can have a period all the way up to delivery but this is a different article.
If you do not have period like me I can go 3-4 months without one and they cannot figure out why except my body is stressed, my hormones are all over, my body has gained so much extra weight but that kind of wasn't the case. I was and am going through pre-menopausal. I have all the signs but the doctor will not diagnose it which is fine. I have plenty of nurse friends who help me pin point what was all happening. The best thing to take for this is Vitex (chaste berries). Vitex (Chaste berries) help regulate your body and hormones and can help jump start your period.
It can cause extreme fertilization if you are needing help getting pregnant this can also help you but if your not be sure to use protection. It can also help with your period pains so that is a bonus.