Why!?

Why do PMS and Pregnancy symptoms have to be the same!? I plan on testing soon but seriously. My symptoms are: heart burn/acid reflux. Nausea. Mild cramping. Mildly sore breast and Im super emotional! I know those can ALL be PMS symptoms too. But I wish the symptoms were different so we could tell! Ugh. Wish me luck. Hoping for a positive test soon.