make this make sense

so my BIL has this new GF, she’s sweet we’ve only met her a few times but we always make her feel welcome.

anyways she was pregnant with another mans baby when we first met her, 17 weeks pregnant. we’re a very accepting/understanding family so we didn’t have an issue with it. if BIL is happy, so are we! anyways fast fast forward 2 weeks and she has a miscarriage and i feel HORRIBLE as i’ve had one too and 19 weeks is pretty far along to lose a baby i know it couldn’t have been easy physically or mentally. i knew we wouldn’t see her for a while, my ass was a hermit for weeks after my MC cause i was just so upset. but to my surprise they came over for dinner last night(one week post MC) to inform the family she’s pregnant again with BIL baby this time.. i’m sorry??? what?? this isn’t even physically possible, is it?

she was FOR SURE pregnant before she showed us an ultrasound and all the information was correct her name the date her birthday and even how many weeks she was correlated. she even posted all on facebook announcing it posting bump pictures and she called me while in the hospital having her procedure to ask me for advice about life post MC.. but now she’s one week post miscarriage, pregnant again? i’m not understanding here!