Random symptoms and AF 2 days late but BFN!

So I have had numerous symptoms lately. My boobs have been really sore but it's off and on. Earlier today I was very constipated and it just hit me out of no where! And my CM has been very yellow lotion looking but it's quite a bit if discharge. My lower back hurts a little but I am in the army so being on my feet all day might contribute to that but it's not that normal for me to have it since I am used to being on my feet all day. I had mild cramps the past couple weeks. I have taken numerous tests in the morning but always get BFNs :(