Bed Bugs, what now? (please help)?

I woke up this mourning to an itchy back. turns out I got attacked by bedbug(s) in my sleep. the area of attack is "localized" to a 10 cm (4 in.) patch on my shoulder. I have had pretty bad allergic reactions to bedbugs in the past. If i get bit by one the bite swells to a hard mound over 8 cm (3 in). After examining the bite marks, I say it was two different bugs that got me. I washed everything, and have done my best to find tell tale signs of bedbugs with no luck. What do I do now? Since I've washed everything do you think they are all gone? Should I call an exterminator? Or Do I wait to get attacked again, to make sure they are still around? I am lost. help. please.