It’s a good time to be Pink: she and hubby Carey Hart are expecting their first child and she just landed her third No. 1 on Billboard’s Hot 100 with “Raise Your Glass,” one of the two new  tunes on her greatest hits set.

Will it stay at No. 1 for more than one week? Not if the recent past is any indicator. In a move that hasn’t happened in more than 20 years, there have been five different No. 1 songs in five consecutive weeks, according to Billboard.

So who may we be toasting next week? Possibly Katy Perry, as “Firework” shifts 6-2 on the Billboard Hot 100 and 4-1 on Hot Digital Songs.

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Last week’s No. 1, Rihanna’s “Only Girl (In the World)” falls from the top perch on the Hot 100, but it rises to No. 1 on the Hot 100 Airplay chart, giving the pop queen her sixth chart topper.

Bruno Mars, who earned a remarkable seven Grammy nominations on Wednesday, continues his winning ways, as “Grenade” bursts 17-10, giving him two songs in the Top 10 of the Billboard Hot 100.  “Just the Way You Are” jumps 7-4 as a result of strong digital sales, most likely due to the song’s appearance on “Glee.”

Cee Lo changes “F*** You” to “Forget You” in his bid for radio play, Enrique Iglesias modifies “Tonight (I’m F****** You)” to “Tonight (I’m Loving You)” for the same reason and it worked like a charm. The clean version of the song explodes onto the Hot 100 at No. 18, Iglesias’s highest debut ever on the chart.

Follow Melinda Newman on Twitter at @MelindaNewman