Could I be pregnant? - Please help!

So for the past week I've thought I was pregnant. I had (and still have) all these pregnancy symptoms. My period was late but a week-10 days ish. But then I statted getting cramps (again) on sunday night, went to the loo and there was pink on the tissue so I thought great my period has finally arrived. Put a pad on, went to bed, went toilet the next morning (yesterday) and nothing was on the pad. Yesterday afternoon I went toilet, wiped, and there was brown on the tissue, and a bit of red blood so I put a tampon in. Wore it for about an or so and there was barely anything on it. Little bit of red blood but mostly brown, so I didn't bother putting another one in. From then until right now I have nothing. No blood, no pink, no brown. So was it just a really short (and late) period or was it something else?? Is it possible I could be pregnant? Could it have been implantation? But if it was surely I wouldn't get pregnancy symptoms beforehand? Is it possible to bleed slightly when you're maybe 4-5 weeks pregnant?

I should add I took two tests, one last monday and one last Tuesday, both had an extremely faint line so not sure if it was actually negative or not lol.