confused

it's been 14 days since my period ended. like for 4 days last week I was bleeding light pink looked like implantation bleeding (from what I googled). this week Monday no blood Tuesday no blood Wednesday no blood today I took a test and it said not prego also no blood until literally about 35 mins ago and it's a darker shade pink but a lot more. What the hell. I have been experiencing nausea, nipple sensitivity, dizziness, sleepiness, back pain, and light cramps on an off for about week. every time I go to the dr they say nothing is wrong. o yeah n every time I orgasm sometime I have stomach pain.