Yes, pregnancy symptoms and PMS symptoms can be pretty much the same. PMS is however followed by a period and pregnancy not, but you know that already.
The only real early symptoms of pregnancy are your periods stopping altogether and the hormone change that can be detected with pregnancy tests.
If the man is good with pulling out, it is still a very efficient way of preventing pregnancy. It is just not good if you want to prevent pregnancy at all costs and can't afford a slip.
With perfect use (urination before sex, pulling out in time, keeping sperm away from the vulva, not having anatomical problems, cleaning up correctly) only 4 out of every 100 couples that used it for a year will get pregnant according to the latest statistics. If you are not careful, only 19 of every 100 couples that used it for a year will get pregnant. This is in comparison to 75 of every 100 couples that do not take any precaution that get pregnant.