pinkali have just read through this thread and really glad to hear all's well with you.
I wanted to tell you my story so far in case it helps in the future. I had the most awful cramping during implantation at less than 4 weeks. It was only at night and felt like really painful period cramps, after the third night I woke up early and did a pregnancy test and it came up positive. I was overjoyed (and nervous)
Then the cramping stopped and I panicked that I'd lost my only 'symptom'.
Just over a week later started spotting brown blood. It was very light and not at all painful but continued for a few days so I was sent for a scan. Scan at 5+3 was fine, a pregnancy sac that measured right but too early to see anything else.
The day after I had awful cramping and the spotting got heavier. For another three days I suffered further cramping and spotting. I was on holiday at the time so could do nothing but wait and see. The cramps stopped but the brown bleeding continued, along with bits of endometrium lining, throughout the holiday and then stopped the day of my follow up scan (2 weeks after the first).
Much to my surprise and joy we saw a baby with a heartbeat in my tummy! I'm now 12+1 and am due a dating scan next Monday.
The reason I'm posting this is because I believe that the initial cramping I had during implantation caused an amount of internal bleeding (egg burrowing deeply) which didn't come out until the following week. And because my cervix was closed it took over 3 weeks to expel all the old blood. So if you do get any brown blood over the next few days don't panic straightaway, it could be from your initial cramps.
I believe the second wave of cramping I experienced was from a combination of the discomfort of holding old blood near the cervix and over-stretching my bladder during the first scan.
I've learned through my experience and from the wonderful support on Mumsnet that cramping and bleeding in early pregnancy is common, a lot more common than we're led to believe. It doesn't necessarily mean it's over.
Still waiting for the all clear that I'll get with the next scan, but since my last scan at 7 weeks I've had no bleeding or period-like cramps. I get the occasional twinge in that area, but for me those are reassuring growing sensations.
Hope that helps. I know how worrying the first trimester can be (has been) and you're doing brilliantly to be thinking positively about it - that's gotta be good for your PEA.