Is this already a sign of infection?

i had a misscariage last saturday night and passed the fetus and the placenta right away, that night i bleed heavily and had a severe ache in my abdomen. the next day which was sunday, the bleeding had lessen and had a light pain in abdomen, i thought it would end that easy but last Monday, my abdominal pain came back and was worse than last sunday, it was really painful that i can barely stand due to its pain. the bleeding came back but not as much that it could fill the entire pad, tuesday i felt the same..until today..it is really painful and im worried about it :( is this just normal? or is this already a sign of infection? please help me.. :(