Sexual diseases could spike when lockdown is lifted, it is feared.
Alliance MLA Paula Bradshaw said Stormont should get the message out about safe sex as it plans to ease restrictions and allow people to meet indoors.
Ms Bradshaw, who sits on the Assembly's health committee, said: "We are not good at discussing such issues, but there is a real threat that we will see a spike in crisis pregnancies and STIs. Obviously at the minute people's interactions are very much halted.
"And we have to recognise that on the far side people will be keen to get out and we need to make sure they're reminded of the very real threat that they could face a crisis pregnancy or contract a STI which could have long lasting consequences."
As well as public health campaigns, Ms Bradshaw said sexual and reproductive health charities should be properly funded.
She said the campaigns needed to reflect the reality - and diversity - of people's lifestyles.
The Alliance MLA added: "The frustration amongst the charities I have spoken to are people's lives are all very different and we have to ensure public services reflect that reality as opposed to how we would like people to live their lives.
"There's the high level campaigns, the likes of Public Health Agency (PHA) could and should be running around safe sex, but also then to make sure those front-facing charities and voluntary organisations who work with people are properly funded going forward."
According to the latest figures, the number of new STIs in Northern Ireland is rising.
In particular, there has been significant growth in the diagnoses of gonorrhoea, the highest recorded number in the country to date, and infectious syphilis, while new diagnoses of genital warts decreased. The figures are detailed in an annual bulletin released by the PHA last August, using information from genitourinary medicine (GUM) clinics.
The 'Sexually Transmitted Infection surveillance in Northern Ireland 2019: An analysis of data for the calendar year 2018' report shows that new diagnoses of chlamydia increased by 6% - 1,787 diagnoses in 2018 compared with 1,684 in 2017.
New diagnoses of gonorrhoea rose by 30%, a jump from 679 in 2017 to 882 in 2018, while genital herpes increased by 8% - 501 in 2018, an increase of 38 cases.
New diagnoses of syphilis rose by 72% - 86 cases in 2018 compared to 50 in 2017.
Meanwhile, there was a drop of 10% in new diagnoses of genital warts - 1,436 in 2018 compared with 1,600 in 2017.