Most employers have some standard language in their employment offer letters that says the offer is void if you lied to them during the hiring process. That's standard for everyone they hire. That doesn't mean they think you lied.
Employers vary in how important they think educational credentials are, and the same employer may vary from one position or department to another. But even if they don't think the credential is so important, most employers still want you to tell the truth about whether or not you have the credential. And it sounds like you did, so you have no problem.
When I interviewed for my first job out of college, the interview was during my last semester of school. I didn't have my degree yet, but was on schedule to get a degree soon. During the interview process, I was clear with the employers about the situation. I got a couple of offers, one of which I accepted. The offer letters all had language on them saying that the offer was contingent on my receiving a degree and submitting my transcripts within a certain time period. That was their way of saying, "we know you don't have a degree now, but you need one for this job".
I'll join the chorus and say that, if you didn't misstate your credentials, and they say they want to hire you, don't be afraid by that standard language in the offer letter. Congratulations on the new job.