Measuring different 20 week scan with MFM

Sammy Jo • MN | 30 | 💍 | 💙 8/18/2018 | #TWINS 💜💜 01/20/2021

At my 20 week MFM Appt my mono-di twin girls are measuring about 6 days difference. Is it normal to see that difference now? Just curious if you experienced something similar?