I am 18. My cycle days usually 31-33days. My February period was normal on time (Feb.13) On March 4th I spotted a whole day. My next period was due March 18. I didn't come on till March 24th. I took a pregnancy test March 20th it was negative. My next period isn't due until April 28 And Yesterday (April 10) I started spotting but it didn't stop yet. Ive been spotting for more than 24hrs. What could be going on?