My brake have recently becom spongy, meaning I have to push the petal all the to the floor and pump them. I have check the brake fluid level and it is ok. I have also noticed that it seems like only one brake , passanger side front seems to be working. Would the most probable cause of this be the master cylinder going bad?
No. The most probable cause would be air in the lines and a bad (stuck) brake caliper.
This is not something you should ignore, even for a day or two. Next time you might find you have no brakes.
The lawyer for the person or persons that you hit is really going to love it when he finds this thread proving that you knew you had a brake problem but kept on driving anyway.
spongy brakes is a sign of air in the system since air compresses and fluid wont
I hope you plan to fix this immediately. This is dangerous!