Los Angeles, California - Heidi Klum has been busy on social media lately and her latest post sent her fans into a frenzy of speculation over the model: could she be pregnant with her fifth child?

Heidi uploaded a stylish black-and-white portrait of her all-natural self on Instagram. In the photo, she clearly has a bun in the oven. Although it can't be too recent – the German has been showing off her perfect figure – many wondered whether it was a hint. Could the 47-year-old be pregnant with guitarist Tom Kaulitz's (31) child?

But it soon became obvious that Heidi had other reasons for posting this older snapshot – it's a tribute to her son Henry Günther Ademola Dashtu Samuel, who was born 15 years ago on the day.

"15 years ago today you came into the world. I feel so proud you are a part of me. You are the twinkle in my eye and the love of my life Happy Birthday Henry ... may your birthday be as special today as you are," wrote the former Project Runway host. She also included a heartwarming photo of Henry as a newborn.

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So Tom and Heidi are not expecting parents, which is a bit sad. The two lovebirds have been together for more than two years, and they tied the knot last year.

Although there wasn't any big news, the images and sentiments expressed are still beautiful.

And after all, who's to say there won't be an exciting announcement sometime in the future?