HELP weird spotting

So I just had a baby in November this past year and im still breastfeeding. Me and my husband have been trying here lately for another! My period was supposed to start on the 12th and nothing. Naturally, i took a test and it was negative. All week i had been nauseous, had heartburn, bloating, hungry, and more tired than usual. So come the 14th, me & my husband had sex. We both finished and i went to the bathroom to pee and there was light pink blood. It wasnt a lot by any means. I got up the next morning and went pee and it was brown. It wasnt even enough to get on my underwear though! So come that night, after no spotting all day, i had started spotting only this time it was bright red. Its been going on for 2 days now, going back and forth between light pink and bright red. I haven't had too many cramps at all and im just losing my mind. Any help or advice from other moms?!