High risk for pre term labor

Violet • I am happily taken by the love of my life.

Ladies I have questions I hope to get some insight! I have a short cervix we found this out at my 20 weeks ultrasound. So I was put on vagina progesterone suppositories. I tried two different kinds for about three weeks. I had to stop using them because I was allergic to the compound they put the progesterone in! Now my high risk doctor that is working with my midwife said he doesn’t think it’s necessary I put me on progesterone shots. ( I don’t want to here how I shouldn’t be seeing midwives. They are nurse midwives I will be delivering in a hospital and have a back up plan if I go into early labour.) my question is why wouldn’t he want me on the shots if I can’t use the suppositories? I really don’t like my high risk doctor at all he is short, dude and doesn’t explain anything. Had anyone ever had this experience??? Please give help me understand! My cervix measured at 21 mm (millimeters) and it should be 30 mm (millimeters). I’m nervous because my mom had his problem and delivered my younger sister at 23 weeks. HELP!