Infertility & becoming an aunt again

I'm 31 and have never been able to get pregnant due to thyroid and pcos. My bf and I stopped using protection a year ago. Back in 2018 both his 21 yr old sister and my brothers 20 yr old fiance got pregnant. My nephews are 9 days apart and are the first grandbabies. My bf and I are both the oldest in our families .. my nephews are a year and a half now and tonight I found out his sister is pregnant again even though she's been on the pill since having her son. Is it wrong that it feels like a kick in the gut and all I wanna do is cry? The day my brother and his fiance had their baby, I literally walked to my car and sat there crying. I'm happy and love my nephews but I am jealous :(