What Are The Chances Of Pregnancy Having Blood Test Negative?

hello, i have a question is there a possiblity for someone to be pregnant although all urine and blood test come out negative? i also had a vaginal ultrasound and nothing showed. i press my abdominal area and feel some type of air bag. Something that i felt in my previous pregnancies. i came out negative in all of my test until i had my belly. i am not ready physically or economicly to have another child what can i do?