@MrsWinslow - Here's wishing you a nice, healthy singleton intrauterine pregnancy and healthy baby!
A person with an ectopic pregnancy will often have normal pregnancy symptoms. She'll miss her period and have a positive pregnancy test, her breasts will be sore, etc. Now, a normal intrauterine pregnancy can cause some cramping and spotting early on, but the cramping should be fairly light and even (and you should call your doctor or midwife just to be safe anyway). A tubal pregnancy will be on one side or the other, so there may be pain or cramping on just one side.
The best thing you can do to protect yourself is just be aware of your body. Read up on Fertility Awareness--it will help you time intercourse and know exactly when to take a pregnancy test. And once you conceive, trust your instincts. If something feels wrong, call your doctor or midwife. If it's the middle of the night, go to the ER and get checked out. Don't worry about them laughing at you or thinking you're just a nervous first-time mom! Put your health first (closely followed by baby's health).