delayed menstration

My • i am 27, happy married i have a 4 year old son. from mission hills california, 91345. hit me up.
i have been delayed for almost 2 months now i had my last menstration last january and till now it didnt come. i tried 8 pregnancy test but came out negative. yesterday i used the clear blue and it say's negative. whAt is wrong with me? give me an advice. im so worried