why am I sad when it's for the best

We aren't financially or living in a home big enough for baby #2 we both agreed school would be the next step before we start trying i understand and I am content with these measures to give both our current child and future child the best but why am I so so disappointed that my pregnancy tests keep coming up negative there's very little possibility of us getting pregnant we are taking precautions seriously but I can't stop taking the hpt and feeling so depressed days and weeks after getting a negative