Can someone please weigh in?

I am currently not trying for a baby, but wouldn’t be upset to be pregnant. My period is the latest it’s ever been at 14 DPO I tested negative however I peed 45 minutes prior and I don’t think I peed on the stick for the full five seconds. Also, there is a chance I miscalculated my DPO as I’m not actively testing ovulation and just doing my best to guess it. My cycle is considered late at day 28 and I’m currently on day 31 which has never happened to me before and so far, I have no sign of a period. I’m having mild on and off sharp cramping, if that makes sense, I’m having a lot of nausea. I was constipated, but now I’m having the opposite issue. There were little floaters in my pee this morning and I’m having sharp pain in my nipples and none of my usual period symptoms like acne or anger. I’m really sad but not angry. I also have so much discharge and it’s really thin. I’m currently at what I think I is 16 or 17 DPO, but like I said I could be wrong. I’m also have shortness of breath and lightheadedness. I know if I was pregnant then I should’ve tested positive at 14 DPO, but I’m new to this and it could be wrong. Also an increased heart rate which is probably one of the weirder symptoms I’ve had.