I wouldn't panic about your period being irregular, it could be ovulation bleeding or anything, I recently had ovulation bleeding, then three days later a period for a day, then my period started AGAIN yesterday and my periods have rarely been irregular. So don't think you're the only one with strange periods :)! It's highly unlikely that you are pregnant, so don't worry too much. All you can do is wait for your period and see what happens :)!xo
Also, going 'deep' like that in a sex-like act would never rupture a fertilised egg, so don't worry about that.
If you're a virgin and you've masterbated with an object that was used pretty deeply then that's why you've bled. You've irritated your cervix in a way that it's not used to yet and so it caused some bleeding.
As for the 'dry sex' you describe, there is always a small chance whenever the penis comes into contact with your vagina - but it's small. Also accompanied by the fact you were literally just finished your period, makes this even more unlikely to cause pregnancy so I wouldn't worry about that.
However for your peace of mind, I would suggest wearing a condom in future for that sort of thing, it could spread STDs, if not pregnancy so always better safe than sorry.
And don't worry about sounding stupid, you're just not educated much in relation to sex etc. I would maybe suggest educating yourself more on the matter before engaging in any more such acts. Anything you need to know, don't hesitate to message me and I;ll try help the best I can.