Most religious and magical symbols have been in use for a long time, so much so that a lot of people feel that appropriate symbols need to have some sort of historical validity to them.
However, the fact is this is the 21st century, and there are concepts and situations common to us that were largely or entirely unknown in ancient times.
Recently, a question was asked in the forum about historical symbols for sterility. I confessed I was not aware of any, in large part because sterility was generally something people wanted to avoid rather than attract.
I suppose one answer would be to use a fertility symbol and then deface it some way, whether by drawing an X over it or outright destroying the symbol. But a symbol specifically referencing sterility escapes me.