@MummyMayo1988
I am so sorry for your friend OP, and it must be SO hard for her. 
I cannot imagine how I would have felt and coped if I was unable to conceive.
At the same time, you should not feel bad/guilty for being pregnant.
Don't pay attention to people bashing you. If your friend had come on here saying she is pissed off with her friend having 3 kids, and wishes she would piss off talking about it, coz she is struggling, SHE would have been on the receiving end of the curt comments.
I am sorry to say this, but I don't think you and this particular friend are right for each other at the moment.
I had a friend (from childhood,) who had a steady boyfriend at 14/15, and she was still with him at 20, and she constantly put him before me, and frequently let me down. I never had a (steady) boyfriend til I was 20. I was with him for 6 months when hers ended their relationship.
She was really upset, (understandably,) but then stopped contacting me, and never returned my calls or answered my letters (early 1990's, no email or texting then.) So I was there all the time for her, even when she let me down frequently in favour of her bloke, (and I didn't have one!) but she didn't want to be near me when I was with someone.
I thought she may have been a bit sore from being dumped, but then she never bothered answering ANY of my attempts to contact her. After about 6-8 months I gave up.
2 years after she stopped contact, she contacted me because she had a new fella. (we were 22 by then.)
Fastforward a year to when we were 23, and I told her me and my fella were getting married. 'What the fuck,?' she said. 'I thought I would be the one to get married first, not YOU.'
And she was really annoyed. Then THAT fella finished with her a few weeks later.
I invited her to the wedding (6 months later,) but she never came, and then I never heard from her for about 3 years - despite contacting her quite a few times.
THEN she got in touch again when she had a new fella, flat, car, and job. Shortly after she contacted me again, I announced I was pregnant. Cue her fucking off again and stopping contact again.
I moved towns when my DD was born several years later, and never contacted her, and she never knew where I went. She knew where my folks lived, but they moved to a new house too, not long after we moved.
3 years later, I visited my old town, and her mother stopped me in the street, and said 'Lyn has been trying to contact you but your phone number is dead, and you don't live at No 3 anymore, and your folks have moved. RING her. Or come see her. She lives at 19 Church Street with her husband.'
Unsurprisingly, I never contacted her. Not then. Not ever.
Whether she was sore, upset, bitter, angry, jealous or whatever. She is no friend if she refused to be there when things are good for me, but not great for her. She always wanted ME there when my life was average (or below average,) and HERS was good.
Many people I know have things/have had things I would desperately like, but I don't ghost them because they have it and I don't, and then run after them to be friends again when my life improves, and then fuck off again when they get something else I would have liked.
As I said, you and this friend are not right for each other at the moment. I would give her a wide berth. As I said, I am sorry she is struggling with conceiving, but it's very unfair to take it out on you.