11dpo...too early?

based n glows calculations I'm 11dpo, my AF is regular and I'm due to have it on Monday...I do have PCOS and am TTC for #1 for past 7 months...I have cramping in my lower belly, sore lower back, sore nipples, slight nausea and heartburn thru the roof....I don't want to be symptom shopping but my body def feels different from when I get AF....I have taken 2 tests these past two days using fmu and both have come up bfn....I've been reading some of ppls others posts and they have gotten bfp around the same time...I feel like my mind and body are playing tricks on me!!! anyone else feeling this way?