[mnm8409]

The last time my boyfriend and I were sexually active was August 5th. We had unprotected sex and I was expecting my period within 3 or 4 days. (Yes, I know.. unprotected... STUPID!). He didn't "finish" inside me, but there was of course wetness. A few days later I got my normal period as expected.
A week or so later I started having what may have been pregnancy symptoms and after asking around I decided to take a pregnancy test just in case because that's what most people seemed to be telling me. I took two about a week apart and both were negative when checked within 5-10 minutes, but it was about September 7th and I was worried that my period may be late (I'm irregular so it's always hard to tell) and that the "symptoms" I was having could be from pregnancy (things like headaches, nausea, fatigue, "morning sickness" [happened x2, may have just been a bug or bad food though], irritability, mood swings... nothing too major).
Since I still didn't have my period I made an appointment for a clinic to get tested (this was around the 10th), but they didn't have any openings till today, September 13. So yesterday I go to use the bathroom when I wake up and I notice some light pink spotting. Of course, I'm thinking implantation bleeding. A few hours later (3 or 4) I start getting a heavier flow (my normal flow is VERY heavy, so this is still light for me.) which continues throughout the day. Now today it's back up to my normal very heavy flow, does this mean I'm for sure NOT pregnant? Should I still go to my appointment tonight? Is there even the slightest possibility I AM pregnant?
Yes, I know these may seem like silly questions, but I'm just very stressed and worried about it all. Any responses would be fantastic!

[DoulaLC]

Very unlikely that you are pregnant. The sex, while unprotected, was right before your period was due. Not the most likely time to become pregnant... although there is no time that is 100% safe.
Implantation bleeding, if you were to notice it, would have happened within the first two weeks afterwards.

It most likely is your period, just being a bit off as you have experienced in the past.

Might be passed the time already, but it wouldn't hurt to keep the appointment, find out for sure one way or the other, and have some peace of mind.

Obviously, as you already know, always use protection from now on and reduce the chances of unnecessary worry.