Car won't start after oil change...95 OBD-II KA

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I just changed my oil, and now I can't get the car to start. First time trying to start it cranked, started, then died. Tried it again...crank, start, die. Now it will crank endlessly and won't start. I know I didn't do anything wrong...it's just an oil change, and I've done many in the past with no problems. Dipstick reads full but not too full. I'm thinking it maybe have something to do with this problem I've been having, but I don't know. Any ideas?? I need to get this fixed ASAP as it's my only car! Thanks!