25 weeks brown spotting

Alyssa Rabara-Brokate

Hi yall, this is my third time having brown spotting during the second trimester. Had it first around labor day, then again sept 29th and here we are again. My ultrasounds looked great, cervix closed, no infections. Has anyone else experienced this and gotten an answer as to what causes it. My husband is stationed out of the country so I haven't had sex, either.