I learned the hard way that plumbing is not something to try if you have no advanced knowledge of it. My bathtub tiles started to fall off once and I realized it was possibly due to a leaky pipe in the wall. I got my tool belt, broke a hole in the wall and swore I could tackle this on my own. Instead of ending up with some pretty decent plumbing repair, I did a shoddy job and made things worse than they were at the beginning. I ended up calling in someone later on to fix the things that I did wrong.
You should always call a plumber when you have problems instead of running out and acting like you know what you are doing. The time and money you save in the end will make it all worth it. Sure, you will have to pay a good amount for repairs, but that pales in comparison to the amount you will have to pay if you make the problem worse and there are numerous issues that someone will have to tackle in order to get your plumbing back in working order. Save the trouble and hire someone right away if it is needed.