Hi.. Welcome to HEALTHCAREMAGIC.. As per your query in case if you have excessive bleeding tendency and you are already taking g aspirin that has anti platelet activity or blood thinning tendency therefore if any surgical procedure carried out now can cause excessive bleeding that can be fatal.. So first of all consult an Oral Surgeon and get evaluated and a thorough clinical evaluation and investigation like bleeding time, clotting time, Thromboplastin time etc can help in ruling out the exact condition of your clotting activity and then only proceed with treatment.. However even after everything comes normal still you should stop aspirin intake for a week before the biopsy procedure after consulting your treating physician.. After biopsy if the area of biopsy is large then stitches will be placed.. Also resuming normal activities can be done in an hour but it will also depend upon the area involved in biopsy.. Hope this helps.. Regards.