I did type all this last Wed but it didn't post so here I go again with my thoughts on the Jac/Jonny thing. Nobody probabky cares but as they were a favourite couple of mune I might as well give my two pennies worth.
The reveal that they have been sleeping together again makes complete sense to me.
Whilst they are too different, and there's been tpo much hurt on both sides to make a full relationship as life partners work, we saw that they had an instant sexual attraction to each other which never really seemed to go away. It was the one area they always seemed to click and enjoy, even when bickering about other issues. So, if neither are dating anybody else it might be very easy for that line to be crossed as they spend time together anyway for Emma's sake.
On a deeper level, if Jac has actually been thinking she'd like another baby, then given she isn't in a relationship and might well doubt she ever will find a man she can.propermy make it work with, Jonny could seem like a good candidate.
She always gave the impression that she wanted her child to have a father for the benefit of the chikd so don't think she'd go down the sperm donor or pick up she never tells route. She knows Jonny is a good Dad, she mentioned it to Mo only a few weeks ago, and they are going to be in each others lives to a major degree at least until Emma is an adult anyway so would a second one make that much differencw? Practically speaking, it would be much simpler and cleaner (for want of a better word) than there being another man involved that she isn't in a full relationship with but needs to coparent with.
Jonny might even be keen if she suggested it given he always said he wanted kids, plural.
Of course that might not be her thinking at all, but it does seem weird that she onky has these scares with Jonny and she didn't look upset or worried at the beginning of the episode when talking to Sacha and she must have suspected she was at that stage as she did the test soon afterwards. So, for all the "after I've decided what to do about the pregnancy" stuff, it seems clear she was okay with it,would have had it, was disappointed she wasn't pregnant and will prioritize any baby, or even chance to have a baby over her own health.