Irregular cycles suck

So i have irregular periods(my last cycle was 43 days) but ive had other cycles in the past be 30 something days, so i dont know when I ovulate or even when to test for it without spending sooo much money. So i have two apps and one says I ovulated on the 10th (so im 10dpo today) and the other says the 16th (id be 4 dpo today). Ive taken tests 8,9,10 dpo (according to the first ovulation date) and all are negative (frer). Im getting discouraged and sad bc ive been experiencing some symptoms and i hope im just too early. My hubby has to travel for work to another country where zika is a risk so we wont be able to have sex for 6months, so if im not pregnant this cycle im going to be so incredibly sad..