Right. What i was trying to say before my phone was mean to me was...
With a household income of £37,000 you will be absolutely fine!! You will also get child benefit of £20 a week because your wages are under the new threshold for loosing that.
Don't forget that once you have a family your spending priorities will change without much conscious thought. Like for example i used to spend my disposable income on a Radley bag now and again or £100+ nights out or clothes. Not that i had a huge amount of spare cash, but when i did i would save up and so these things. Now i have a family i have reprioritised. I no longer think spending £150 on a handbag is okay for me, because i would rather spend the money on something nice for the kids. I don't go on anything like as many nights out and when i do they are far cheaper. I don't feel like i am missing out by doing this, and i never made a decision to stay in more, it's just the natural cross-over from being a DINK (double income no kids) to being a family.
Plus, i know it's scary thinking about how children cost more the older they get, but it all just kind of happens. You all just kind of grow into it.
Basically you guys must have spare income now based on what you've said. All that will happen is that you "cut your cloth accordingly" as my mum will say. If your finances are comfortable as you are now then they will continue to be so as long as you're sensible. Just don't get into debt or mistake luxuries for essentials.
Only those people who are having financial difficulties now should worry. For those people i would strongly advise getting their finances straight before having kids. Babies are cheap, but it creeps up on you how much more you spend as they get older. If you already have disposable income then you adjust your spending and it all just kind of works, but if you are stretched already i can only see that adding strain on the relationship and making things harder than they should be.