Worried :(

[Lindsey]

Okay, I'm going to start by saying if you don't want too much information, don't read this post!
I have always had normal periods... I started birth control when I was 18, and have switched kinds a couple of times with no problems. I have had a bit of spotting a couple of times but only if I accidently miss a day or two of my pills in a cycle... then I take double the next day like I'm supposed to. And I know that spotting in those circumstances is normal.
Well last week I had my period just as I was supposed to. I ALWAYS start on Tuesday and end on Friday. This time it extended a bit into Saturday, but that wasn't a big deal. Then I was fine for Sunday, Monday, and Tuesday.
Last night I was staying at Scott's house, and it started again. Not a whole lot, but enough that it was there and I was really worried about it. I know my body and this is not normal.
I was texting my cousin all night, but not getting any replies. She's normally who I run to with problems like this. As soon as I got home this morning she replied with "Okay, don't be scared but please go take a pregnancy test. I had the exact same thing happen when I got pregnant with Kally. Implantation bleeding. It could be either that or a miscarriage. Just please take a test"... And I LOST IT. I was crying so hard. I texted Scott immediately, and he told me he'd handle work for the morning, just stay home and take as much time as I need, and he'd be there to talk to. We had a very tiny oops a few weeks ago, but that's what I'm on the pill for - backup. And he was absolutely sure it couldn't be pregnancy. And I had not missed a pill. And I did get my period. My cousin told me that it doesn't necessarily mean anything, and asked me again to please take a test.
Finally I got the courage to go to the store, buy a test, drink three glasses of water, and pee on the stick. There were a couple of gruelling minutes, and I was still bawling when I went in to look... but it was ABSOLUTELY CLEARLY NEGATIVE. I have never been more relieved.
The problem is I'm STILL bleeding and a bit crampy, and I just want to know if someone else has ever had something like this. I am calling my doctor tomorrow for an appointment, but until then I just want some support. I can't talk to my real mom about this stuff so I thought I'd turn to my internet moms...