I think a spike in pregnancies is possible, whether that will translate into live births I'm not sure.
Women conceiving who aren't in the best of health due to either covid or unable to access regular healthcare as easily as usual may result in more mc.
Also as pps say those couples who need help to conceive will have struggled to get that support so that will delay/impact them.
May also be more abortions due to concerns about health of mother, health of foetus plus economic uncertainty.
I think a more likely time for a baby boom (a small one nothing like the post war one) will be late 2021 as people return to "normal" and are less concerned about health issues and economy (If Brexit doesn't turn out as bad as feared economically too) and are back to meeting up for casual sex too.
If anything, the divorce rate will be going up yep! Can definitely see this happening! Not just due to time spent together in lockdown but because of poor economy again which puts additional pressure on relationships.
I heard on news earlier 600,000 jobs have been lost so far and that won't be the end of it.
Most people will also be aware that welfare support is likely to be further restricted as a result of the economic impact, I wouldn't be at all surprised if this govt stepped up to a 1 child limit for children born from end of next year.
Contraception is generally speaking much more reliable than it was at the times of previous baby booms too.