This is your journey and whatever might bring you comfort is the most important thing.
If you do go ahead I can't recommend using protection enough. (I would say this even if you weren't pregnant - but obviously this weights the need even a little more).
I indulged - a lot - and my insistence on using a condom kept some boundaries in place for me - as well as keeping me safe from potential infections or diseases that he might have.
Your boundaries might be different - I have heard of ppl here on SI that set other boundaries about what they wouldn't allow to happen that helped them feel safe - while still allowing them the comfort of some intimacy.
For some reason I needed it. It was an educated risk that practicing safe sex helped to manage. I found comfort and release in our sex. Sometimes I cried during or after, sometimes I felt angry - but for some reason during that period abstaining was not an option for me.
If I decided later that I didn't want to reconcile so be it. I could still decide that now. The fact that I was having 'meaningless' sex with him in that period was irrelevant to my journey of reconciliation and I made that clear to him at the time - that it didn't mean anything with regard to the amount of work in front of us.
I say 'meaningless' - but the truth is it helped to reform the circle of 'us' once I had full disclosure.
But look after yourself - physically and emotionally.