You'll see a miniature little alien baby rather than a jelly bean. You'll see arms, legs, a definitive head and body and you will even see them moving around (if they're not sleeping).
You may see them bring their fingers to their mouth or "wave".
You won't see them scrunched into the fetal position just yet unless they just like to lay that way. There's enough room for them at this point that they can still stretch out.
wow! You are already almost 13 weeks! I am so glad that you are doing well. I hope that everything is good at your next u/s appointment and cycl is right google is usually the best way to see what will be happening at that time.
if you google 13 week ultrasound it will show you pictures of what you could see.