Some women notice changes in their energy level, mood, or breasts -- a lot like having PMS. Other signs might take you by surprise, like fainting, a shift in your sense of smell, or more bathroom visits. Your changing hormones kick into gear, even before you take that pregnancy test.
Most Billboard Hot 100 No. 1 Hits By Artist. The top spot on the ranking of the artists with the most No. 1 Hot 100 hits hasn't changed in 45 years, with the Beatles (20 leaders, tallied in 1964-70) fending off closest competitor Mariah Carey (18). Notably, Rihanna has entered a tie, with Michael Jackson, for the third-most Hot 100 No. 1s (13), all since her first, SOS, in 2006. See the All-Time Charts: Billboard 200 Albums | Billboard 200 Artists | Hot 100 Songs | Hot 100 Artists.
Bruno Mars' 10 Biggest Billboard Hits are based on actual performance on the weekly Billboard Hot 100, through the chart dated Feb. 8. Songs are ranked using an inverse point system, with weeks at No. 1 earning the greatest value and weeks at No. 100 earning the least.