My bathtub drain all of the sudden came to a snails pace. Allmost a complete stopage. I started with liquid plumber and a later a plunger. No help. I have pulled off the overflow drain plate and tried to run a snake down, but I get stopped at what I assume is the p trap and it will not proceed into it. All the other drains in the house and especially that bathroom work great. Would a hair clog stop it up that sudden? Is it time to call a Pro?