I am unmarried , I have skipped my period for 3 months and now from dec 20 , 2011 I am having my periods till now earlier I was having my period only while using restroom , bt now from 4 days having a very high flow.. Please suggest me something and also I have taken certain medicine bt it is not working worth...

Have you seen your doctor about the irregular bleeding? There can be several possible causes but it would require examination. If you have seen your doctor, did they do an ultrasound to check if anything could be seen? What is the medicine that you are taking? Was it prescribed by your doctor?

How old are u?
U better go to a gynec. This is not something you ask online. It's almost 2 months since you started bleeding. STOP LOOKING FOR ANSWERS HERE AND GO TO A DOCTOR.
I strongly feel you are under age and had unprotected sex. Hence you are scared to go to a doctor or tell your parents. Am I right?
No one knows you here, feel free to ask for suggestions, but not on matters so serious.
If you are scared to tell your parents, talk to some elders you are close to. Get their support and ask them to talk to your parents. Don't wait any longer.

Firstly I am 21 yrs old and I never ever had any type of sex with anyone and I have consulted about 10 doct till now bt none of them had came up with a +ve response that's why I had chosen this way... and there was nothng in ultrasound report it was clear and I had taken several medicines like gynae - c.v.p , regestrone , trapic mf , ovral g etc.

vatonsale,

So far the doctors have tried various hormonal remedies, but it appears that they are not beneficial for your condition. When you had the ultrasound, was it an transvaginal one? If not, this sort may help them to get a better view.

The next steps would be more invasive. There are some procedures, a D & C for example, that your gyn may decide would be necessary since the medication route has not proved effective. You may want to discuss what options you have available to you.