Hi Minimatron and welcome to Belly belly.
No, you shouldn't panic! Any sort of blood sends any pregnant woman into a state of fear - this is natural. However many many women have some blood loss during pregnancy and go on to carry their babies to term. I bled on and off for the first 14 weeks of my son's pregnancy. He was born healthy and gorgeous.

I am sure many other women with similar stories will visit you in here and this will help ease your mind.

On a practical level don't have sex until the bleedihg has stopped. I think it would be wise to see your gp who may order an ultrasound just to have a peek at your baby. However if the bleeding is minimal he/she is likely to wait until you are later in your 6th week for an early ultrasound. By then you should see a heart beating away.

I truly understand how scary this is but try not to panic. Big hugs and do call you gp.