BAM

Hi Guys,
I'm in the middle of planning my trip and this is my dilema...

I am staying in southern Belgium (near Liege) for a couple of weeks before I travel and I need to get to Istanbul by the 21st of July to start a tour.

I was originally planning to get a train up to Amsterdam for a couple of nights then fly but now I need to leave Liege on about the 14/15th so I have a bit longer.

I was thinking of finding my way by train but then I realised that the trains stop somewhere along the between point A and B and I would need to bus it for the remainder. I am also not so sure about going through Romania and Bulgaria by myself (I'm a 21yr old female who will have a big pack)...

Any suggestions on which way I should go? I can get a direct flight from Amsterdam or find my way through Eastern Europe on my own...