What Can Cause Delayed Periods Despite Taking Mensovit Forte?

Hi...i am 23 year old married girl...i did not get ma periods for 2 months...wen i hd a pregnancy test it was negative...but stil i took mensovit forte kit to get my periods...after taking tablet also i din get my periods n its been 3months i din get my periods...i am really getting scared pls help me to know wat should b done to get my periods....