No Period since March 12th? questions?

I had my last Pd on 03-12 and i am normally right on track with them. My husband had a vasectomy 21 years ago. and with me being late could it be that they grew back together? Please help I am worried. Went for preg test this am and wont have the results until Thurs am. And another strange thing starting last night and thru today i have been mad at the world and not sure why then just busted out crying. This is horrible! and constant headache since last thurs. please any info will be much apprecieated