Many thanks for your patience. It is clear that you are guilty of misconduct here because you lied to your employer to get time off from your work. So in a loose sense, if you have profited from this in having given time off on full pay, you may have defrauded them. However, do not worry too much about this as it is not a criminal issue and it is not as serious as it may sound just because the word fraud is mentioned. It is more of a misconduct matter where you have been dishonest.
The employer is entirely within their rights to discipline you over this. I understand that you are pregnant so if what you did was due to you being pregnant and not thinking straight at the time, then certainly use that to your advantage. It does not provide you a full excuse for your actions but it can reduce the severity.
Whilst a dismissal could always be the option the employer takes, I do not think this would be the case here, based on the fact it was an isolated incident, you have a long and, hopefully, clean record and it was likely affected by your pregnancy. I would therefore expect a warning, which you should accept. If the result is a dismissal then you should consider taking this matter further.
This is your basic legal position. I have more detailed advice for you in terms of the rights to have to challenge this if it results in dismissal, which I wish to discuss so please take a second to leave a positive rating for the service so far (by selecting 3, 4 or 5 stars) and I can continue with that and answer any further questions you may have. Don’t worry, there is no extra cost and leaving a rating will not close the question and we can continue this discussion. Thank you