I've had a contraceptive implant inserted in my left arm a bit more than a month ago. I was at the end of my period at that time, which was very regular thanks to the pill.

Two weeks after having it fitted in, I had my period for a single day. Then it stopped and started again five days later. Since then, I've been continuously losing small amounts of blood.
This happened to me when I started taking the pill, but my period went back to normal as soon as the second month started. Does anyone have any experience of this with implants? Am I more likely to keep on losing blood in this manner than to have a normal period again?

Finally, because I was losing so little blood, I used pantyliners. Then I switched back to tampons because it irritated me. I've been wearing tampons for about a week now but it still itches and today I've noticed that my labia have swollen to be incredibly big (about 1cm in width).
The last time this happened to me was in late August when I wore pads during my (real) period. It would itch and then my labia had swollen up to an impressive (and scary) size for a few days.

Is there anything I should be worrying about, or is it much much likely to be the use of pads?