Ist bei uns unbekannt das Wort, aber in USA sehr gebräuchlich...

Das ist ja interessant. Das heißt also, das Wort "unattractive" wird nur im übertragenen Sinn verwendet und nicht für Personen? Darüber habe ich mir noch nie Gedanken gemacht, aber es scheint wohl so zu sein.

Könnte ich auch unattractive verwenden? Homely klingt für mich ein bisschen "hausbacken"

Jetzt habe ich noch ein Wort gefunden: unappealing
Wie wäre es damit?

I feel unpretty habe ich im Ohr. Und zwar kommt das in einem gut 10 Jahre alten Lied von TLC vor, wenn ich mich nicht täusche.

Unattractive is fine, too. I guess it isn't in Leo because it is a regular negative.

un•attract•ive /ntrktIv/ adj.
1 not attractive or pleasant to look at: an unattractive brown colour
2 not good, interesting or pleasant: one of the unattractive aspects of the free market economy attractive
un•attract•ive•ly adv.
OALD

Danke, Archfarchnad -gb-! Ich dachte schon, ich bin ganz plem-plem... Es ist schon ein bisschen verwirrend, wenn man zu "unattractive" zwei Übersetzungen findet, aber die eigentliche Grundbedeutung "unattraktiv" nicht dabei steht.

"Unattractive" and "unappealing" are both good. I would not recommend "homely".

But I think Mike E's idea is even better: use "I don't feel very attractive" or "I don't feel very appealing" instead of "rather unattractive/unappealing".

If external appearance is the main issue, then I would say "attractive" is better than "appealing".

or "I have the feeling of being not much to look at."

if it can be somewhat slangy:

I'm having a bad hair day

"Sinne von Aussehen und Anziehungskraft auf das andere Geschlecht" - In this connection, you could also say: I seem to lack sex appeal/ I have no sex appeal. In the "good old days" this phrase just meant - I don't appear attractive to the opposite sex.

Can't speak for the rest of the UK, but in Northern Ireland to be called 'homely'is to be complimented. It means friendly, pleasant,good natured.

Thank you, JGMcI. Some years ago, in Scotland, somebody called me very casually: 'homely'. I was never really sure what to make out of it. You just gave me some hope, when I started to feel nothing but ugly.
*veryslightlyrelieved*

IMO 'unattractive' (or 'not very attractive') is the only really good solution in a sentence with 'Ich fühle mich.' I agree that there's no reason it shouldn't be in LEO, and I would think you could do a New Entry simply with a reference to this thread as evidence, or at most a quick dictionary citation or two.

'Unpretty' isn't really a normal word; 'unappealing' doesn't necessarily refer to appearance, as GeorgeA says; 'unalluring' is too fancy and contrived for ordinary conversation; 'homely (AE)' and 'not much to look at' describe permanent traits, not temporary feelings; and 'bad hair day' now is more often figurative than literal, meaning just a bad day in general on an emotional level.

I agree with those who suggested that "unattractive" or "not very attractive" are best in AE in the sentence given. "Homely" is common, but being "homely" isn't something that can be magically be fixed by tomorrow, except perhaps in fairy tales, so as hm--us pointed out, one doesn't normally "feel homely today".

Please repunctuate my previous post.
...fairy tales. So, as hm--us pointed out, one doesn't ...

I wouldn't want anyone to be influenced by my poor punctuation.