supposed to start but only had a light pink spotting!

Hi,
I am 39 years old & had unprotected sex on March 28th with my fiance, who is also 39. It was my first time in 7 years. He told me the he did ejaculate inside me & that i could be pregnant.
My period normally starts at the end of the month, but this time on the day it was supposed to start i only had a light pink spotting that morning & nothing else for a couple of days. Yesterday, i started to release a thick, dark discharge which is even thicker today but it only comes out when i urinate (nothing on the pad).
In addition, over the past few days i've experienced headaches, severe fatigue, increased appetite, leg cramps (back of my legs), a light earache (which i never have), 3 days of constant heartburn, and milky clear discharge from my breasts with little raised bumps on them. I have a 15 year old son & he has 5 children. Can you please shed some light on this?