Ay sis, totally normal yan sa injectable, marami akong kaibigan na nag-inject din at ganyan din ang experience nila, especially pag baguhan pa lang sa family planning! Ang hormones talaga ay medyo maglalaro first few months kaya yung heavy bleeding at cramping ay common, pero since sobrang dami pa rin after two months at may sakit pa, mas maganda talaga i-confirm with your OB on Sunday para sure lang at ma-rule out kung may iba pang reason. Bawas-bawas usually yan by the third or fourth month, pero every body is different, so don't worry too much, you're doing great ha! Let me know what your doctor says.