Unfortunately I can relate to your story, but not because of a past molar pregnancy, but my past ectopic. I had NO issues when DH and I started trying in January 2011, thought I might have PCOS but that wasn't a big deal. Regardless, I did my research and felt great about my odds. In April when the pain started the thought of an ectopic passed through my mind, but I brushed it off knowing that less than 2% of pregnancies become ectopic in someone that doesn't have any markers to cause the ectopic. It happened to me. I didn't understand HOW that could happen. I'm healthy, never any STD's or hell even slight infections, so HOW and WHY would I have an ectopic? And WHY did it have to rupture? HOW could I almost die from just wanting to have a baby? I swore the odds would be against me for the rest of my life.
Fast forward a year and lots of meds later, literally within days of my ectopic anniversary I got pregnant again, and we lost that one very early too...for no apparent reason. I gave up, and somehow got pregnant with no medical assistance. First thing that crosses my mind when I see those pink lines - I'm going to need surgery again for an ectopic. Waiting for my first ultrasound (only 2 days but still) was the most terrifying of my life. I knew it'd be in my tube and I'd be rushed into the operating room again. Then we saw the little sac, and it was in the right spot. A small victory, but one of the biggest reliefs I have ever felt. The tech said it was SO CLOSE to being ectopic again that only millimeters got it into my uterus and ok.
That being said, it took me a long time to begin to connect with this little one, and some days I catch myself thinking that I may lose Lucky, but I shake myself out of it. I call this baby Lucky because (amongst other reasons) it's something I haven't ever felt until now, when luck and maybe God or Fate or the powers that be were on my side. Each ultrasound and heartbeat brings me closer to my baby, and I'm finally starting to realize this is real.
Sorry this is so long-winded, I just wanted you to know you are allowed to feel however you feel. This appointment will bring back horrible memories and be tough as heck, but once it's done and you see your baby you can get past that milestone and hopefully begin to feel better about this baby. You will get to that enjoying pregnancy stage, it just may take longer than most.