The doctor is recommending an amniocentisis any advice on what to do?

I'm 19 wk pregnant and i've been spotting the whole time. I've had 6 ultrasounds and my last one they found 2 markers and they are recommending an amniocentisis. My blood test for an AFP came back normal. It's hard to make a decision, i've heard some stories about how it hurts real bad. I mean how do you make this kind of decision have it done or not to have it done. I'm scared to have it done and i'm scared of the results, but at the same time I want to know what is going on with my baby. Can anyone give me some kind of advice. I know the decision is mine and i'm the only one who can make that choice. I would like some opinions or if any one has been in this situation just comment I would truely appreciate it. My appt is next week and i'm terrified, i've gone back and forth to have it done or not to have it done. Please help. Thank you so much. GOD BLESS