Having sex @the end of my cycle unprotected can I become pregnant? I spotted after my cycle I'm super crampy ovaries and belly I'm 4 months postpardum

Hard to tell. The return of ovulation postpartum is different for all women. Breastfeeding will delay it longer than if you are not breastfeeding. The first few cycles postpartum may be unpredictable and make ovulation hard to predict. That is why having unprotected sex in the first 6 months postpartum is risky. The spotting and brownish dsch are not uncommon at 4 mos postpartum. If desired, consider Plan B med.