Op l am much much older than you and have been through a few bad economic times, my advice is,
Pay off all debt ( not including mortgage here) as fast as possible and build a secure savings fund. Save,Save,Save.
Do example budgets showing different scenarios, ie if you lost your job or DH lost his jo, see if you can cover your costs, both now, and if you were on maternity leave.
Then factor in childcare options, see where that would leave your finances.
This will decide if you can TTC now or not. ( Admittedly it is not a great time l am afraid from a medical point of view.)
Then look at the house option.
If you delay TTC for a few years, you may be able to upsize now, there will be great buying opportunities, and mortgage rates are low.
Note, as you will want security to start a family later consider a very long fixed rate (10 years) to give you certainty of outgoings. This is probably the best time in my lifetime to do this, as rates are so very low and will not stay this way for ever so securing a rate for a long time makes sense.
Next look at emergency planning, if you upsize home and find youself struggling what can you do to bring in income? Spare room for lodger? Side business self employed? look at all options... proof reading £15- £20 per hour from home freelance/computer based marketing.....Before you TTC get different skill sets, take short courses in things that you can do self employed.
An example, an old neighbour of mine trained as a hairdresser on leaving school, then after 2 years went to uni and did a business degree and went into finance.
She was a casualty of the 2008 crisis and lost her well paid job overnight as did her DH.
No body was hiring in the city, so she started hairdressing at home in a spare room, and freelancing, within weeks she was very busy and said it paid the mortgage and bills until her DH found another role over a year later. Oddly enough she has continued and said she earns 35-40K a year plus tips on her own terms.
Not saying you should train as a hairdresser, but consider self employed skills as a back up, and to maybe work around future Dcs.