Glad to hear things are going well and you got to see the little heartbeat. I hope you can relax now.
Well they say the first and last trimesters are usually the most stressful times for pregnant women. I would say that is probably true. I bet for women that have had fertility treatments they would be more likely to be stressed the whole pregnancy. I got better as time went on. Much better after the twenty week ultrasound and once I could feel the baby kick.
Just do your best to rest and take good care of yourself.