Microsoft released build 15031 last week for Windows 10 and Windows 10 Mobile devices on the Fast ring, but don't expect to receive a new one this week. Dona Sarkar, Microsoft's chief of the Windows Insider Program, said earlier today through her Twitter account that no more Insider builds are going to be released this week:
As she pointed out, build 15031 has been the focus of the final Windows 10 Creators Update Bug Bash, which began February 3 and ended last weekend. Because of the amount of feedback received, the engineers at Microsoft are still focused on triaging it.
We're getting closer to the RTM version of the Windows 10 Creators Update, which - as Dell revealed in January - is slated to roll out in April.
Source: Dona Sarkar