I need help from people with previous experience spider bite,bruise(pulled muscle), something else?,?

My husband last week woke up in the middle of the night to sharp pain in his leg, there was a small blister(white) with red around it not in a circle or bulleys just red, the next few day the blister went away no bite marks are open wounds formed just bruising the normal red and maroon colors he was not experiencing any pain, it has now been a week and the bruise is alotbigger there are still no open wounds nor bite marks nor pain just a larger bruising area with red and the outskirts of the bruise are a light greenish yellowish color the bruise is not in the shape of a bullseye there is no pain no streaks of lines through no open wounds of spider bite marks. He and I are worried about the bruise getting bigger. Now my concerns are: 1 if its a spiderbite where r the marks or open wounds? If it was a very posionous spider wouldn't the skin have started opening within the first 3 days 2. If its a pulled muscle where is the pain and why did it start off as a blister? 3. Does the spreading bruise with the light green around it mean that the bruise is healing? Please help ill take all comments because google is just narrowing it down to a spider bite or bruised pulled muscle, my husbnd juz barely moved to CO and he has no current doctor there I just need to kno if y'all think whatevvr it is, if its gettng better or worse?