Symptoms and bfn

My period was due 2 days ago but all im getting is lots of mucousy discharge. My boob are also very tender and TMI ive been a lot more gassy lately. Ive had 2 kids and the discharge, boobs and gas have all been typical pregnancy symptoms for me but i dont remember getting them until after i tested positive. I took a test yesterday and then again today with FMU but im just getting bfn. With my second baby, i tested negative on day of expected period but positive a week later so i know theres still time but they crazy strong symptoms are just throwing me off. Has anyone experienced strong syptoms before getting a positive? (Im using the walmart cheapy tests so i dont know how sensitive they are)