I know we're not doctors

Selinaa

But I had a baby in September and I've been ebf I had my period like normal until April which was my last period I haven't had it since. I've taken a pregnancy test in the end of June it said negative. Ive also gained 5 lbs with walking everyday and eating as normal or less. I jufst hate going to the doctors. So is this normal to not have your period after having it as normal for a few months