Are they gonna make it to the end?

Conflict in romantic fiction

I'm in the middle of chapter 4 of my NaNoWriMo project; got stuck a little partially because of This Thing Called Life getting in the way, and partially becuase I've started having doubts.
Are my characters really three-dimentional or a little flat?
Is the plot believable and not contrive?
Is the conflict strong enough to keep them apart for 200 pages?

The plot of a romantic novel can be described in three steps:
1. Boy meets Girl
2. Boy looses Girl
3. Boy gets Girl back.
They have to meet on the first page (or at most the first chapter; I've got them together on the first page), feel that instant chemistry, but usually don't realise they've fell for each other until half way through, so something MUST make it impossible for them to be togheter for the rest of the book, otherwise my novel will be finished on page three.

I admit, the biggest problem I have is with the conflict, which is one of the most important ingredient of a romance, and actually the one which incorporates all the other. Believable, fully fleshed-out characters can only get involved into a conflict, which derives logically from their personalities and will resolve it in a believable way.
The events of the plot need to reflect the progression of the tension between the hero and the heroine.

The emotional tension (a.k.a. conflict) is what keeps them apart and makes the reader turn the pages, biting their nails and worrying how they are going to get together. The obstacles to intimacy and happily-every-after need to be strong enough to prevent them from getting together and they should be of internal (values, character traits, ambitions) rather than external (circumstances) nature. If miscommunication is the reason they are still not together in Chapter 8 (out of 10) I'd better make sure it's yet another effect of their personality clash.

In the two medical romances I've finished reading so far and one of the unfinished the conflict is really well thought-out. Looking at the personalities and their values of the main characters I wondered if they were going to ever be together. External conflict (related to work) was only an addition to the internal one.
Of course they made it at the end. It wouldn't have been a romance if they didn't.
For a change, the conflict in one of the unfinished ones felt so forced and artificially 'blown up' that I put the book down. In the other unfinished the external obstacles to being together (they discover they've fallen for each other in chapter 4/5 and then had a major medical and family crisis to get over before they can walk off into the sunset), although very exciting (a cyclone and a lost child) were not interesting enough for me to read on.

I have a difficult task.
So Anne hates when men assume that because she's so attractive she's silly and earned her professional position only because she's slept with her boss. In the first scene Geoff thinks that Anne is just one of those pretty, silly girls, who he doesn't have time for. And then he learns she's his mate's little sister, and then that she's his... new neuropsychologist, whose help he needs badly to rescue the reputation of the unit he cares so much about.
As for her. well... Falling for her boss is a/ unprofessional (and she is desperate to come across as professional), b/ would be a perfect evidence that she is one of those pretty silly girls who...

Anyway, I haven't written a single word in my NaNo novel for 2 days, I'd better get back to it and see if they are going to make it to the end and happily-ever-after.