"I want to make sure before I see my family that I don't carry the virus back."
First-year university student Steffan Leonard is planning to book a Covid test before travelling home to his family in Swansea.
Across Wales, universities are offering tests to students who want peace of mind before they go home for Christmas.
But Steffan is concerned he may have to self-isolate on his own after others have left his university halls.
Most university teaching is due to move online by Tuesday and students are being encouraged to travel by Wednesday 9 December.
The aim of offering tests from this week is to make sure anyone who tests positive can complete their period of self-isolation in time to get home for Christmas.
However, Cardiff University has had its own saliva testing programme since the start of term, and any positive cases are then encouraged to have an NHS test to confirm the result.
They have had around 6,000 bookings as part of a programme for asymptomatic students running until 15 December.
One of them was third-year economics student James Messenger, who said he would also be self-isolating in the days before he returns to his family in Oxford.
"They are very appreciative of the measures that I'm taking to prevent them from possibly having it," he said.
Cardiff University's vice-chancellor, Prof Colin Riordan, said they could not force students to take tests.
"What we need to do is to explain very clearly to our students the benefits of taking a test which is that they may be asymptomatic and positive," he said.
There are also questions about what happens in January when term restarts.
Lois Campbell, from Llandeilo, Carmarthenshire, and in her first year studying Welsh and journalism, thinks it would be unwise for everyone to return from their Christmas bubbles to university unchecked.
"I think they're going to have to put a scheme in place which means everyone can return to university safely. We might have to self-isolate [beforehand], nobody knows," she said.
Cardiff University said it was planning a phased return and the continuation of its testing programme for students arriving back.
"We do have slightly different starting dates for different degree programmes anyway so that's helpful," Prof Riordan said.
"So we've got plans in place... and refining them as the situation develops."
NUS Wales president Becky Ricketts said she would like to see an all-Wales approach to student testing when they return to universities and colleges in January to avoid the circumstances they faced in September.
The Welsh Government and Universities Wales said they were working together to ensure students can return safely in the new year.
What if the test is negative?
Cardiff University is reminding students that even if a test is negative, they should still follow the rules and take all necessary precautions to keep themselves and others around them safe.
The Welsh Government is also advising students to minimise their social contacts and their risk of catching and transmitting the virus.