Always scared I'm pregnant on the pill

I'm on the pill. Have been for 7 months and before I was ttc/pregnant I was on it for like 9 years. I have never missed a pill. I take it at EXACTLY 10pm every night. Me and my husband have sex literally once a month (sadly) and yet I'm always so nervous that I'm pregnant. Like I start my period pills tomorrow and because I feel no period symptoms I get nervous. Or because when i was pregnant my symptoms were like having a period so when I do get symptoms I still get nervous! Like logically I shouldn't be nervous and I never was before but now that I have a baby and I REALLY REALLY can't get preg right now I worry myself sick.