What Causes Delayed Periods And Early Pregnancy Symptoms While UPT Is Negative?

I am TTC and this was our first month trying. I am 32 and have two other children. I am 5 days late on my period and had lots of sex around ovulation (which I feel) and have had a lot of early pregnancy symptoms. took a test on first day o f missed period and it was negative. when i feel my cervix, it is low and slightly open ( about a finger tip) and also very soft. I had a ton of yellow, stretchy cm and when i checked my cervix again i had a blood tinged mucus on my finger. then checked again just now and got brown small glob but no period. i have never been late and when i get it, i get very heavy flow. Am I pregnant???