4 weeks & blood clot

Hi, I'm 4 week pregnant and suddenly I had a spotting dgn small blood clot. I buat ultrasound, and the dr said can see the baby's heartbeat and it's too small. Also said it's a threatened miscarriage. The doctor recommended me to go to hospital and get an injection that could either strengthen or weaken the womb. So there is a chance of getting a miscarriage. What should I do now? I'm so worried 😭 I don't know what to do! It's so confusing and heartbreaking coz its my first pregnancy! #firstmom #ingintahu #pleasehelp