Havent started my periods but have had a few spots and discharge. my breasts feel like they are leak

hi.

Firstly i am a proud mother of two gorgeous girls who i fell pregnant with on the pill.

and now for my question:

the last time i had the injection was beggining of July 2012, i was suppose to go again on the 09 October but havent had time to. lately (13/11/2012) i have been waking up feeling like i have babalas and heartburn in the middle of the night. i have been feeling very tired lately and craving gas cooldrink or sugary food. my stomach has been feeling tight in the lower abdomen area. i have no energy anymore. i also feel nausea when coughing. i havent started my periods but have had a few spots and discharge. my breasts feel like they are leaking but they are not. ( i have had unprotected sex with my husband, which he puts a condom on just before he cums)

Can anyone explain or know why this is happeniing? or could i be pregnant.