Pregnancy symptoms or signalling something else?

I will try and keep this short. I have 3 children, 9 years, 7 years, and 11 months. I never had breast tenderness with my first two, and very early on (first symptom) with my youngest. Very recently, (past 2-3 weeks) I have had nipple sensitivity (erect at slightest touch/air temperature change), heavier discharge, and heartburn. Does anyone know if these are symptoms of anything else besides pregnancy? I had my tubes tied february 28th of this year, so pregnancy is highly improbable.

Mia2012-09-08T20:39:52Z

Could just be PMS or hormonal changes. On, that note, I was at the doctor just recently and there was a lady there that was 5 weeks pregnant and had her tubes tied! Her youngest is one. So it IS possible.