Tmi.. warning..!!

I was suppose to start af on the 18th19th. I usually start the night before it's due. this time.. I've been dealing with diarrhea and no af for 4 days! we have been ttc our rainbow baby for almost 2 years now and I am trying not to get my Hope's up. not knowing when I accurately ovulate is hard. my body seems to change a lot. so I took a cheap test.. it was a slow reader. the positive screen was blank but smeared blue color.. and negative was slow to read. very very light twinges on left side. lower back ache.. sleepy.. I just sent want to get my Hope's up. going to retest tomorrow I think?

hoping and praying for a BFP!!! has anyone dealt with diarrhea and slight cramps.. 4 days late bfn.tests and turned out pg?? or should I just give up hope?