i usually ask my wife to cut my hair before pesach, but this year she was particularly overloaded with preparations and i decided to not ask. but now my hair is bothering me terribly and there are still about three weeks to go until lag baomer which is when i usually cut it again. is there any way to be lenient in such a situation and have her cut my hair now?
ב"ה Shalom, The Rema (סי' תצ"ג: ג) as explained by the Mishna Berura, mentions two major Ashkenazi minhagim in regard to Sefirat Ha'omer. Some don't take haircuts from Pessach until Lag Be'omer and some do not take haircuts or shave from the second day of Iyyar until Shavout (besides Lag Be'omer itself, which again is allowed). According to both Minhagim, there are 33 days in which people don't shave and take haircuts. The Mishna Berura further says that one cannot follow both customs at the same time because that would be contradictory. However, we have found in the Poskim who have said have said that in a place where there is no set custom, one may follow one custom one year and another custom a different year, since the tradition of not shaving for 33 days is upheld one way or another. Following this position, you would be allowed to cut your hair up till the second day of Iyyar, but then you wouldn't be allowed to cut your hair again until Shavuot, besides Lag Be'omer. (חת"ם סופר או"ח סי' קמ"ב, אגרות משה או"ח ח"א סי' קנ"ט, אגרות משה או"ח חלק ב סימן צה, פסקי תשובות סי' תצ"ג: ס"ק י"ג. ) [This answer does not address the issue of taking a haircut in honor of Yom Ha'atzmaut, which I've addressed in a different answer.] All the best