I've been tired all day is this normal in pregnancy?

I have been tired all day Iam 28 weeks pregnant. My eyes are very heavy but i cant sleep. My little boy has not been well he has got a cold, sore throat and a cough. The other night he woke up and vommited after having a coughing fit. He only vommited twice but he was ok the next day his eating has been ok hes had no diarheoa. I was just wondering if he had a bug or it was because he has a cough and because he's congested he vommited. I am only asking because iam pregnant and pregnant women are more prone to viruses and infections. I've had a sore throat and been very tired all day. I went to bed at 12 last night and got up at 10 today so could it be too much sleep. I am very concerned as i have this phobia of being sick and it is a pretty bad phobia as iam under cbt for it and iam on medication for the phobia. Answers much appreciated.