miscarriage at 17 weeks

I'm 6 weeks postpartum and I gave birth to my sleeping son 6weeks ago on April 22nd at 17 weeks . Doctor said he was healthy and no one knows what happened to him . Me and my husband are trying to conceive since . And heard after mc or even giving birth you are very fertile but for some reason we still have not gotten pregnant after this loss . I do not know what is going on my bleeding comes and goes but it's not super heavy to fill up a Pad or anything it's just on and off and on and off idk if this is a light period or if I'm still bleeding from from miscarriage because I did give birth to him but I do have moderate to very light cramps . Like today . I wiped and I seen blood please help and share with me