If you had given it shoulders (or oversized breasts) I would have thought the similarity was entirely on purpose, but I think that even if you don't care if it looks like the end of a penis it doesn't resemble a mushroom which would imply a change of sorts is needed.
The face down section of it looks rather flat, and I think it could stand with a bit more curve.
You also have an extra bit of light coming from the left that isn't hitting the shroomhead but is hitting the "body" section.