It took my a few goes with my first pregnancy. I tried the second time but wasn't too fussed. If it helps I'm still breastfeeding at 6 months so it doesn't indicate anything
I really struggled to get much out but the best thing I found was a warm bath and massaging before attempting to get any out
I never managed to do it for my first pregnancy, and the day my baby was born the midwife helped me, turns out I needed to squeeze WAY more than what I thought, it wasn't easy, even for her that day. The following days it was a little easier and then the milk came it all was OK. My point being, if you don't collect colostrum before giving birth, it can be ok too. But if it's really important to you to collect before birth, maybe you can ask a nurse or a midwife for advice or help?
I also found it difficult to collect colostrum with my first baby, so my partner helped me and he was able to do it on his first attempt.