Threaten miscarriage

I was bleeding so badly during my 12 weeks of pregnancy. The baby scan was okay, the heartbeat was fine. I was given medicine to insert in my vagina for 2 weeks & injection until my next appointment. I still have bleeding while on medication & it scares me a lot. I always try to stay positive but mentally it's just hurting. It's my third pregnancy & trying to be as positive as i can for my pregnancy. :')