Light Brown Discharge

Hi Mommies, I am on my 20th week of pregnancy. Last Thursday, I had to go to our office which is located at SM City Clark to get my company ID done. They are sending me back to the office next Month, September. And when I came back home same day from the office, there are 75% of light brown discharge on my undies. I had to change my undies quickly and after 20 mins meron nanaman. So it stopped na the evening. Today, Saturday 22nd of August, meron nanaman discharge ng same color ul until now ng 23rd of August. What does it mean po ba? Is this the what they called AWAS/HUGAS or is this not safe? Thank you po sa sasagot.