Should I be worried if I get bloody stools a week before my period?

It appears that you have two issues which may or may not be related. Left lower quadrant abdominal tightness and pain, which occurs episodically through the day, is described as colic. In a 26 year old gentleman, the causes of left lower quadrant abdominal colic can originate from the bowels (intestines) or the urinary tract (ureters). In other cases, the discomfort can be due to nerve related issues (known as referred pain) or abdominal wall musculature, especially if it is related to movement.

Hi, The description of your symptoms appear to be proctalgia ani. While it literally translate to "pain in your anus", the persistence of your symptoms warrants a physical examination by a doctor. The causes can range anywhere from an anal fissure (tear in your anus), to deep anal infections, to referred pain from somewhere else e. g. coccydynia / pelvic floor strain (from your weight lifting), and stress.