Feel I am at a bit of a crossroads.

In my opinion, give weight maintenance as much effort and attention as weight loss. The reason why people regain weight lost is partly because they stop being purposeful with their diet.

Yes, you need more calories to maintain or you will just keep losing... so just as you learned to cut some stuff out and re-configure what you ate to create a deficit, you need to do the same to bring your caloric level up without feeling stuffed. I recommend adding more healthy fats. Fat is high in calories and is vital to healthy body function. Where you may have cut out butter or cheese to lose weight, add some back in; if you've eaten leaner cuts of meat, choose something different - have a steak instead of a chicken breast. Use full-fat dairy instead of nonfat and stay away from sugar-free/no-sugar-added/diet/light foods.

If you are not lifting weights, I highly recommend you start. If you lift weights 3 times a week, any time you have a surplus day (from a party or whatnot) your body will be seeking to burn those extra calories to actually create new muscle tissue.

Lift weights, love! Then you can be purposeful with your diet, because you'll want to make sure you are eating enough to build muscle. Also, try to turn your focus from calories to hitting macros--it will help with what might feel like a need to be attentive lest you regain fat. I know what you are talking about with the "weight loss mindset", and I really feel you will have greater success (physically and mentally) by working on goals relating to body composition rather than scale weight.

I agree with the pp that weight maintenance needs just as much attention as weight loss. A few years ago I was super attentive to my diet and exercise, got into awesome shape, and lost about 50 lb. I slowly stopped giving it the attention it deserved, and yep, you guessed it, I gained about 25 lb back! It's totally ok to be conscious of your choices.
Just keep making those healthy choices, stay active, work on building muscle (as other stated) and you'll be fine

Then realised I didn't really want to lose anymore and should be aiming for my TDEE. But then I would be eating what I didn't really need - just wanted! Which didn't feel right, I am so programmed now to aim for losing!

Your TDEE is the amount of energy your body uses in a day, so if you're eating your TDEE, you are absolutely eating what your body needs. You're not giving in, or being weak or indulgent, you are nourishing your body with the nutrients and energy it needs to go about its normal processes. Eating at a deficit is ok for a while while you need to lose weight, but it's not the ideal thing for your overall health. Your body needs energy!

Pay no attention to the "in 5 weeks you would weigh xx" thing. MFP is a calculator, that's all. Other calculators (such as Scooby's) use slightly different calculations and may be a little more or less accurate. The only way you're going to find your true TDEE is by experimenting and seeing how much you can eat without gaining. MFP slightly underestimates mine, so that weight predictor thing would never be accurate for me. The solution to that is - don't "complete" your diary, and you won't see that message any more.

Definitely consider resistance training of some sort, it can do wonders to change the shape of your body. It's also very important for maintaining muscle mass and bone density. I would encourage you to start sooner rather than later. I'm not an expert in pregnancy but I can only imagine that having a strong core would be beneficial to a pregnancy. In my opinion, part of this maintenance process is about self-acceptance. Very few people get to their goal weight and look like their version of a "perfect" body. So, in a way, "getting used to" your body as it is now isn't a bad idea. That doesn't mean accepting defeat though! If you look around the success stories here, there are lots of stories of women who have taken up heavy lifting and just got smaller/firmer without losing any more weight. It doesn't have to be in a gym, you can start with body weight exercises (just google "body weight exercises", or check out nerdfitness) and I bet you would see good results.