It is very unlikely that you tore your pectoral muscle, I wouldn't worry
about that! However, it is very likely that you pulled or strained the muscle. Most of the time, this will get better with rest and relaxation. Sometimes a serious strain can take more than a week to heal up, so I think you have to give this more time. You should definitely not go back to weight lifting or any other vigorous activity involving these muscle groups until you are 100% back to normal. In addition to rest, icing the area and taking an anti inflammatory medication like ibuprofen or naprosyn should help.
If it has been more than 1 week and you are still having significant symptoms, then you should go see your primary care doctor
to have the area examined and to make sure that things are healing as they should.
In the future, it is important to prevent these kinds of exercise related injuries. You can do this by making sure not to lift weights that are too heavy and by giving your self adequate rest days. One excellent strategy, for example, is to alternate weight lifting days with aerobic cross training days.