If you've been given a large feature that involves, say, analytics, there is surely nothing wrong with your standup contribution being:
"Yesterday, analytics. Today, analytics. Yes, I said the same yesterday, it's a big job, but it's going fine. Anyone can come over and ask me about analytics if they like! No blockers. Thanks."
It tells people what you're doing and that it's broadly going ok. If you're five days into something that was supposed to take three days and you're actively embarrassed about this, then that's a problem - but it's a problem that should be discussed at the end of the third day with the stakeholders, not in the standup.