As Flapdoodle said, I probably should not have gone so far as to try to identify it by species given the quality of the photo; however, I remain convinced that it is probably a bedbug.
In the little research I did before my original post, I ran across one site which actually explained what Flapdoodle described above about the apparent arrowhead 'design'. Basically any food they have eaten can be seen through their semi-translucent bodies. Immediately after consumption, the blood meal appears near the head area and is reddish in color. As the meal moves down through the body it darkens to a blackish color.
Near the far end of the body, the tract (the food moves through) narrows taking on a sort of funnel shape. The 'arrowhead' you saw was most likely a blood meal which had reached this funnel shaped region at the end of the body. Although not seen in all bedbug photos, I have seen numerous photos online which show some variation of this same pattern depending on how much the particular bedbug ate and how recently.
I can totally understand why you would prefer not to see this thing as a bedbug; however, it does fit the available information, including what can be discerned from the photo along with your estimate of its size, the fact that it bit you, and even the 'arrowhead' pattern you described.
In view of all of this information, you really should check your home for any other signs of infestation. If your bed has a wooden frame or other wooden components, check crevices of the frame for any signs of bedbug activity, especially droppings. Think back to the time frame when you found this bug. What were you doing prior to that incident? Had you just gotten out of bed? Were you coming in from outside? etc. Also, take note of any red areas (bite marks) on your body.
As I mentioned earlier, if you have traveled (especially with luggage) and stayed in a hotel or motel recently, that may be where you picked them up. Also, if you have recently brought any used furniture into your home, especially upholstered furniture, it is possible the bugs may have hitched a ride in this manner. If this is the case, you should also check the furniture item(s) over carefully for any signs of bedbugs or their excrement. Bedbugs have been known to inhabit sofas and other such upholstered furniture as well as beds. According to some accounts I've read, bedbugs may also hitch a ride on used plush toys (aka stuffed animals).
Thinking back over your activities around the time you 1st saw this bug may help you figure out where you (most likely) came into contact with the bug, and checking suspect items in your home should help you determine if you do have an infestation. I would imagine that catching and addressing an infestation early would probably improve your chances of successful eradication.
