Im not an expert but sometimes B-H can appear worse when you are constipated or with full bladder. I suffer from pregnancy constipation to a very great degree and the time when "it" moves around or down, or something it can cause B-H and it gives me sharp pains.
Having said all of the above, it never lasts for 30mins or so. So that might be concerning and you should tell this to you MF. It might not be B-H at all if it lasts that long. I think 2 mins is already long, although I have had them for more than 2 mins but not much longer than that.