Question about nipples

Nipples are darker, but when I  Iay on my back there not as dark but when I stand up they get real dark and purply. And get spider veins in my areolas, do I trust that as a pregnancy system even when I lay down and they get lighter? Bc I know when you stand up or sit up more blood flow come so they change but I'm pretty sure there way darker then they were before when I was standing or sitting question is which one do I trust? Bc the spider Veins are visible unless I'm sitting or standing and I usually don't have those ever. Haha I know it's kind of a weird confusing question butt if you get what I mean I'd love some Advice haha My period is a week late tomorrow with lots of milky cm and watery cm and other symtoms I don't feel like typing out also successfully used OPKs this month!