...my main reason here is if the system downvoted me or something.
This shouldn't be a concern. The system doesn't downvote you. I think there used to be an automatic downvote applied for some close reasons, but I don't think that is the case any more. Either way, it wouldn't go on a spree like that.
Most likely it's just your garden-variety Serial Downvoter. There's a script that should detect this, but it takes some time. The usual advice is to wait 24-48 hours to let the script run its course. After that:
If the 24 hours has already passed and the suspicious votes have not been reversed, you can then flag one of your posts and explain what happened so a moderator can look into it. It is generally preferred that you avoid asking about them on a site's Meta since details of the investigation cannot be divulged and you won't actually get any information that will be useful to other members of the community.
Of course, it's possible that this is a big coincidence, and those votes didn't all come from one person/user. If that's the case, I guess the mods will let you know about it after you flag it for their attention.
This happened to me a week or so ago (only 8 posts, I think, but all within 3 minutes). It was detected and reversed the following day.