Trying to conceive, lmp was 1/30/21, started lightly bleeding 3days before my expected next menstrual. it was bright red and not heavy like my usual menstrual, used only 4pads for 3days and it's off now. is it implantation bleeding? or early cycle?

The bleeding "three days before" an expected period was probably an early period, but bright red bleeding might also represent a pregnancy outside the uterus (ectopic). Obtain a serum HCG test to be certain about pregnancy. Ask your gyn about a hysterosalpingogram (HSG), which can show blocked tubes, and occasionally clear them: common cause of infertility.