I'm not going to read the other responses (mainly based on your SWH saying people are judgmental; it'll probably piss me off). Give yourself a break, mama!!! It happens, especially in today's society where it's more common for a baby to have his/her own bed/crib in his/her own room. Bed-sharing isn't as common, but oh man can it be a life-saver when baby is sick or teething!!! My recommendation would be to snuggle down with him for a few nights and nurse a lot (if you still breastfeed).
IT HAPPENS, and it could have been worse. You could have been in your own room, comfy and dead asleep in your own bed. Maybe you wouldn't have heard the thump, and even worse, maybe you wouldn't have heard the cry. Instead, you were foregoing your own comfort and sleep needs to sleep close to your son. Therefore, you were closer to him when the incident happened and were able to get to him quickly.
The fact that he fell right back to sleep tells me (a mom x2, going on 3) that he's fine and an ER visit might make you feel better, but probably isn't needed. However, you need to trust your OWN instincts regarding that one :)
All that, his crib still is the safest place he can be if he's not in bed with you and your husband. When he starts feeling better, he'll probably start sleeping better, and you won't feel as concerned that he'll get hurt. Keep in mind, however, that some babies climb out of their cribs a lot earlier than others, and sometimes, there's nothing in the crib to use for a boost. My first never even considered climbing out, but my 2nd learned to climb out around 18mo. She didn't do it often, mainly because I usually got to her when she first started fussing instead of leaving her in there to fully waken :)
We even tried the toddler bed around age 2 1/2, but she refused to stay in her bed. In the end, she was in her crib until age 3 1/2 when we finally put her in a twin bed. If anyone suggested a toddler bed, 7mo is WAY too young in my opinion....