I had a miscariiage on the 22/01/2012. I did a home preganacy test last night and it was a light positive.
Could I be pregnant again?

Depending on your cycle and sexual activity yes. You could have some hormones still in your system from before but not likely. I would Contact your Dr. Could have just been a bad test. What do you mean "light" positive? Did they do an ultrasound when you miscarried? Is it possible you were carrying fraternal twins and only miscarried one?

"Light positive" - the positive line on my home pregnancy test was light.
I did not have an ultrasound when I miscarried, it was a complete miscarriage.
A small ball like thing dropped when I went to the toilet and I was bleeding as if I had my period (TMI... Sorry)
All my symptoms stopped after the bleeding started, I have not been to the doctor since the miscarriage.

HPT's are not 100% accurate. There can be a mistake in how the test was done, etc. It's possible you could be pregnant but its just as possible that there is enough of the pregnancy hormone left over to register on a HPT. The only way to know is to ask your doctor for a blood test. They will be able to tell by the exact hormone level (and if its increasing) on whether this is a new pregnancy or not.