Pegrum joined the Wings on an initial three-month loan from Leyton Orient in September.
The 19-year-old is a product of the O’s academy and made his senior debut for the club off the bench in an opening-day trip to Charlton Athletic in League One in August 2023.
In total, he has made eight senior appearances for Orient in all competitions and has prior experience in National League South thanks to a pair of loan spells last term.
An initial stint with Tonbridge Angels was followed by a temporary stay with Aveley and he now joins the Wings in a bid to secure more first-team experience as Rod Stringer bolsters his midfield options.