Please Ladies Help Me, Now I'm Confused..ahh

Okay, here's the deal. Just so you know, I have a two year old. So i've been pregnant and know how that feels.

My boyfriend and I had the only unprotected sex we've ever had on wednesday night, sept. 21. It just happened and we both were lazy bc I was expecting my period any day. My last period started sunday aug. 21. I normally start around the same date of every month. I have never been irregular.
The friday after having sex, my boobs got so sore and I started peeing a whole bunch. These were the very first things that happened to me when I became pregnant with my son. I knew I was pregnant with him the week of conception. It's crazy. Anyways, over the past week I have had headaches way too often and the urination has not subsided. I get up in the middle of the night now when I normally don't. I was convinced this week that I had to be pregnant, though the tests came back negative. No period. Boob soreness that lasted for a week, complete and utter hunger, fatigue, even heartburn and man, i've been gassy. I have just been convinced and was more or less a waiting game for the tests to show positive, seemingly too early to have the hcg high enough.
Well, yesterday, the 8th or 9th day after conception, I had a very light pink, almost some clearishness to it, discharge. Definite cramping, more so than normal. My periods usually start full blown and not light. This was different. I would only see it when I wiped. I figured, oh my, implantation bleeding. Well, today(oct 1st), the flow is heavier. Practically like my normal flow would be. Howver the color seems a much brighter red and not the deep dark red my period normally is. The cramping is bad too.
My boobs arent as sore anymore, which is odd, still peeing like a freak every 20 minutes.

Now i'm confused...I was convinced I was pregnant. What is going on? Being so late for my period and having all those symptoms makes no sense to me. And now that the flow seems typical, i'm confused. What do you think?