The concern might really be more about the credit score than the down payment. The lower score will create a bigger cost for you to borrow money. But, one must counter that with the possibility of an overall increase in interest rates.
There are a lot of "ifs" to consider.
If your income will remain stable or increase,
If your job is stable, and continued employment is highly likely,
If the cause of any credit bruises has passed,
these are indicators that you may be ready to purchase soon.
If there is a possibility of your credit score raising in 60-90 days, it may be worth it to work on that. How long will it take you to save 20%? If its a long time, the increase in interest rates may make it a better choice to purchase with 5% or 10% down.
The advice you receive from a competent mortgage professional can be invaluable. A frank discussion and review of your income, assets and credit is needed to provide you meaningful advice on this matter.
My response is, "It depends." Although I tried to additionally provide you a few considerations that would guide decisions.