am I wrong?

so I'm 5 days late and I told my fiance and my sister. and my fiance is annoyed that I'm telling my sister that I'm late. I don't know if I'm pregnant but I bought a test tonight and I will figure out if I am or not in the morning. anyways I'm guessing he don't want anyone to know.. and I feel upset because I'm scared to have another baby and my sister is my twin. she has two kids so I feel like she knows what I'm going through.. I kept telling him I need a test and he said he would buy me one but hasn't. so I told him to give me 2 dollars and I'll go buy it myself while he had his friend over. he got annoyed that I'm saying that in front of his friend because he doesn't want anyone to know. I'm confused... I though a hcappy partner who loves someone would tell the world...