Kk, I'm so happy to hear that your second beta is good! So exciting.
I've always done the PIO, including for my ENTIRE first trimester with my son, because my skin reacts to the suppositories and creams and stuff (yeah, that's as unpleasant as it sounds). And with FET's, you need double the dose - 2ml. So I've had ample experience with the shots! Here are some things that have helped me:
-Have a nurse draw circles on your hips in sharpie, so there's no guessing about location. It's not cute, but it alleviates a lot of stress. My husband re-drew the lines about once a week, when they faded too much.
-Definitely warm the oil against your skin before trying to inject it.
-I like to ice my skin for about 30 seconds beforehand. Just don't ice for too long, because you don't want the muscle to be cold.
-Most important tip: Massage the area REALLY well immediately afterwards. My husband did this with a warm washcloth. My doctor's advice was "massage so hard that it kind of hurts." That made the biggest difference in whether I was sore the next day(s).
-Sometimes, I would walk up and down the stairs or do leg lifts for a few minutes after the shot. I don't know if it actually helped, but it always felt good to get the muscle moving when I felt like the oil was making it feel stiff.
-Similarly, using a heating pad afterwards often felt good.
-I use a smaller needle (25g instead of the standard 23g). The downside is that it takes longer to get the oil out from the tiny needle, and it takes a bit more skill (my husband said he had to work harder to push the syringe without it wobbling around). But for me, it's a lot more comfortable than the quicker shot with the big needle.
Feel free to ask if you have any questions!
Sincerely,
Your resident PIO expert.
It helps I promise. 
We have all been there.
when are you plannign for it to be?
