Cramps after period? Please Help :( *Little Long, very detailed*?

So I'm a little worried, though I don't know if I should or not. My mother always tells me the body changes as you get older, so i'm trying to learn this..Lol I'm female, 21 years old. My health has been excellent till about last year towards the middle I started to get Gallbladder problems.. I'm not to good with weird pains, I feel one and instantly go into panic mode because this is irregular for my body, hasn't happened before so I start to worry about it. And looking up online just makes the issue worse, so i'm steering clear from there.

I recently had gallbladder surgery probably two months ago? maybe three but that might be pushing it. I healed up just fine, perfect with no problems. Probably about 3-4 weeks ago I had a bladder infection. I woke up one day busting to piss because I was to damn lazy to get up and go pee before bed, I was really tired that night. I was going often to pee, no burning and it felt like a weird pressure under my belly on the right side. I drank a crap load of cranberry juice and took some pills for about two days and the preasure and peeing a lot had stopped so i stopped taking the pills.

Well about a week ago, three days before my period I got preasure down there again, in the same spot, and I was getting weird pains in my grion area. My periods run very normal like usual, I go about three days and stop, Usually my periods are heavy (runs in the family) and sometimes I do get sever cramping (though it's rare) the first day which I did this time around but that usually isn't anything I worry about.

Well thinking maybe it was just my period acting up I waited. Well a day after my period the preassure and stuff was still there.I feared it was my appendix so I called the doctor about it. I went in speaking about it, he checked for my appendix and it wasn't and he said I could possibly still have my bladder infection. So he sent me home a pee cup because I couldn't go at the doctors at the time (pee'd before I left, I had no idea he would ask for a pee sample :S) Well this was during the weekend so I had to wait. Well it's monday and I havn't gotten a phone call saying if it isn't or not. So I'm taking it that it might be my bladder infection. Weird thing is, is if this is my bladder infection why the hell am I feeling all these this time around and not the other time :S?

He said after i had taken in the pee test to start some pills he perscribed me. I've been on them for about three days now, but today I forgot to take one in the morning, didn't realise I missed it till I was out in about grocery shopping. While walking, lifting some things into the cart I started getting weird cramps around my back and sides, it was like I was cramping again, but I had my period about 5 days ago.

Could this possibly be a bladder infection?

I havn't been peeing really to much but it's been a little foggy? I would guess from time to time, no burning.

Was the cramping I recived was because I didn't take my pill? Can bladder infections even CAUSE period like pains?

As I was taking the pill for a few days the pain in that area had gone away. But after I missed this one day I all of a sudden got cramps and that preassure in that one spot came back, i'm guessing because i was moving about a lot. For the past few days I haven't really been moving around.

I'm still cramping a little bit right now but the pain is slowly dying. :| It's weird. I really need to stop worrying about it lol..but I can't help it. Any ideas?

Sorry this is like a wall-o-text I've seem to gone through a **** load of problems these past few months..I guess you could say im just a little..sick of it..I turn 21 and my insides go to hell..lol

Oh and another thing here, I DON'T HAVE SEX...So i'm not pregnant..