blood in the urine usually indicates a kidney infection that stems from a bladder infection and you also might be running a fever.
You really need to see an OB doc asap and let them know that you have blood in your urine, if not for you, for the health of your unborn baby. also you may want to look in the obstetrics forums, this is a forum for urology (male doctor)... you might find pregnant women with similar cases there.
good luck!
ChrisKenzie is right about the urology forum being for men.
However, you should go in and have a gyn check to make sure everything is fine.
Yeah it could be due to the infection previous and the meds... Some people end up getting bood in the urine when pregnant.. but depends on how much is there.. a trace is normal from time to time with nothing being wrong. but yes see the obgyn