As far as I know my boobs always have "hard cysts" in them. I can feel them if I probe and poke at them, but my boyfriend says he cant feel anything but softness. The hard lumps are the milk ducts, I think thats what they are called. Its normal, my doc has never said anything bout them. Do you go in for check ups or do the self breast exam. If you do notice an unusual lump that gets bigger or was never there before then see a doc.
I think the store prego tests are 99.9 % effective, like they say on the box. I have never known of them being wrong, but there is always that .1% chance. I trust them. But the sure way to know is by a doctor.
You could be pregnant if you had unprotected sex, yes. There is always that chance. My mom got prego with my bro 1 month after getting off the shot. But the chances of that are slim. GENERALLY it takes 1 year for the shot to wear off.
I know how frustrating this is, beleive me I have gone through this so many times. Since you took the test and it came out neg then you can blame you syptoms on the shot. But I do suggest going to your doctor regarding your periods. SInce you havent had a period for a long time they can give you hormones to promote you body to bleed. This way you get on a regular cycle sooner than later.