Help!!! Random bleeding??

Stacy • Married 9-6-14!! Have an amazing 7 year old boy and a 2.5 year old girl. Due with baby 3 6/24/19
My period last month was shorter and lighter than normal. My fertile week is supposed to be starting today but my opks are almost positive (I'll include a pic of today's test) all of a sudden I start having light pink blood coming out. Not a ton but a good amount. Anybody know why this would happen??