positive pregnancy, brown discharge, and earlier abortion...possible miscarriage?

okay well about a year ago i had an abortion and then i just found out about a week ago that i am pregnant again, so im guessing that i am about a month pregnant and lately i have been having brown disharge everyday...not alot but just accosionaly when i wipe. Is this normal in pregnancy?...also about i a week ago one day i had really really bad stomach pains for about two hours and then they stopped and i have had some occasional stomach aches since then but never as bad as that one time ...does this mean that i have had a miscarriage especailly because i have had an abortion about a year ago? please help

about a year ago had an abortion. .got one depo shot after which lasted about ten months. .thought i got my period mid april but turned out to be just brown discharge. .took a preg test a wk after and came out positive. .im about 6wks preg and have occasional cramping and spotting. .after blood test results found out i have a urinary tract infection. .im now taking the antibiotic keflex.