I have had many during my pregnancies.
You won't have many if any symptoms. If its a slow decline as your body adjusts to the dropping levels.

I've had no issues with them & my levels have been very low & my hb has been in the 80-90s.
My levels afterwards have been as high as 500-600 & my hb being 120+
Usually by delivery they were still at 200ish which is good as I always had a PPH.